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72181 = 1929131
BaseRepresentation
bin10001100111110101
310200000101
4101213311
54302211
61314101
7420304
oct214765
9120011
1072181
114a25a
1235931
1326b15
141c43b
15165c1
hex119f5

72181 has 8 divisors (see below), whose sum is σ = 79200. Its totient is φ = 65520.

The previous prime is 72173. The next prime is 72211. The reversal of 72181 is 18127.

72181 = T18 + T19 + ... + T75.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 72181 - 23 = 72173 is a prime.

It is a super-2 number, since 2×721812 = 10420193522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 486 + ... + 616.

It is an arithmetic number, because the mean of its divisors is an integer number (9900).

272181 is an apocalyptic number.

It is an amenable number.

72181 is a deficient number, since it is larger than the sum of its proper divisors (7019).

72181 is a wasteful number, since it uses less digits than its factorization.

72181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179.

The product of its digits is 112, while the sum is 19.

The square root of 72181 is about 268.6652191855. The cubic root of 72181 is about 41.6365079539.

It can be divided in two parts, 72 and 181, that added together give a triangular number (253 = T22).

The spelling of 72181 in words is "seventy-two thousand, one hundred eighty-one".

Divisors: 1 19 29 131 551 2489 3799 72181