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72121728 = 273723833
BaseRepresentation
bin1000100110001…
…11110110000000
312000201011102010
410103013312000
5121430343403
611053452520
71534011300
oct423076600
9160634363
1072121728
1137790138
12201a1140
1311c324a3
149815600
1564e9603
hex44c7d80

72121728 has 96 divisors (see below), whose sum is σ = 222908760. Its totient is φ = 20600832.

The previous prime is 72121697. The next prime is 72121757. The reversal of 72121728 is 82712127.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 72121695 and 72121704.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16900 + ... + 20732.

Almost surely, 272121728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72121728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111454380).

72121728 is an abundant number, since it is smaller than the sum of its proper divisors (150787032).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

72121728 is a wasteful number, since it uses less digits than its factorization.

72121728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3864 (or 3845 counting only the distinct ones).

The product of its digits is 3136, while the sum is 30.

The square root of 72121728 is about 8492.4512362450. The cubic root of 72121728 is about 416.2510811685.

The spelling of 72121728 in words is "seventy-two million, one hundred twenty-one thousand, seven hundred twenty-eight".

Divisors: 1 2 3 4 6 7 8 12 14 16 21 24 28 32 42 48 49 56 64 84 96 98 112 128 147 168 192 196 224 294 336 384 392 448 588 672 784 896 1176 1344 1568 2352 2688 3136 3833 4704 6272 7666 9408 11499 15332 18816 22998 26831 30664 45996 53662 61328 80493 91992 107324 122656 160986 183984 187817 214648 245312 321972 367968 375634 429296 490624 563451 643944 735936 751268 858592 1126902 1287888 1471872 1502536 1717184 2253804 2575776 3005072 3434368 4507608 5151552 6010144 9015216 10303104 12020288 18030432 24040576 36060864 72121728