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28408900 = 2252132412
BaseRepresentation
bin110110001011…
…1110001000100
31222110022200111
41230113301010
524233041100
62452522404
7463320532
oct154276104
958408614
1028408900
1115044033
129620404
135b68a00
143ab7152
1527626ba
hex1b17c44

28408900 has 81 divisors (see below), whose sum is σ = 68422053. Its totient is φ = 10233600.

The previous prime is 28408883. The next prime is 28408907. The reversal of 28408900 is 980482.

The square root of 28408900 is 5330.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 13 ways, for example, as 25745476 + 2663424 = 5074^2 + 1632^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28408907) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 692880 + ... + 692920.

Almost surely, 228408900 is an apocalyptic number.

28408900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

28408900 is the 5330-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28408900

28408900 is an abundant number, since it is smaller than the sum of its proper divisors (40013153).

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

28408900 is a wasteful number, since it uses less digits than its factorization.

28408900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 61 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 31.

The cubic root of 28408900 is about 305.1299276235.

The spelling of 28408900 in words is "twenty-eight million, four hundred eight thousand, nine hundred".

Divisors: 1 2 4 5 10 13 20 25 26 41 50 52 65 82 100 130 164 169 205 260 325 338 410 533 650 676 820 845 1025 1066 1300 1681 1690 2050 2132 2665 3362 3380 4100 4225 5330 6724 6929 8405 8450 10660 13325 13858 16810 16900 21853 26650 27716 33620 34645 42025 43706 53300 69290 84050 87412 109265 138580 168100 173225 218530 284089 346450 437060 546325 568178 692900 1092650 1136356 1420445 2185300 2840890 5681780 7102225 14204450 28408900