72000081 has 6 divisors (see below), whose sum is σ = 104000130. Its totient is φ = 48000048.

The previous prime is 72000053. The next prime is 72000091. The reversal of 72000081 is 18000027.

It can be written as a sum of positive squares in only one way, i.e., 62489025 + 9511056 = 7905^2 + 3084^2 .

It is not a de Polignac number, because 72000081 - 2¹⁷ = 71869009 is a prime.

It is a super-2 number, since 2×72000081² = 10368023328013122, which contains 22 as substring.

72000081 is a modest number, since divided by 81 gives 72 as remainder.

It is not an unprimeable number, because it can be changed into a prime (72000091) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3999996 + ... + 4000013.

It is an arithmetic number, because the mean of its divisors is an integer number (17333355).

Almost surely, 2^72000081 is an apocalyptic number.

It is an amenable number.

72000081 is a deficient number, since it is larger than the sum of its proper divisors (32000049).

72000081 is a wasteful number, since it uses less digits than its factorization.

72000081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8000015 (or 8000012 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 72000081 is about 8485.2861472080. The cubic root of 72000081 is about 416.0169206166.

The spelling of 72000081 in words is "seventy-two million, eighty-one", and thus it is an aban number and an uban number.