72051681 has 16 divisors (see below), whose sum is σ = 103617920. Its totient is φ = 44271360.

The previous prime is 72051671. The next prime is 72051737. The reversal of 72051681 is 18615027.

It is not a de Polignac number, because 72051681 - 2⁹ = 72051169 is a prime.

It is a super-2 number, since 2×72051681² = 10382889469851522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72051601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38436 + ... + 40266.

It is an arithmetic number, because the mean of its divisors is an integer number (6476120).

Almost surely, 2^72051681 is an apocalyptic number.

It is an amenable number.

72051681 is a deficient number, since it is larger than the sum of its proper divisors (31566239).

72051681 is a wasteful number, since it uses less digits than its factorization.

72051681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2856.

The product of its (nonzero) digits is 3360, while the sum is 30.

The square root of 72051681 is about 8488.3261600860. The cubic root of 72051681 is about 416.1162785930.

The spelling of 72051681 in words is "seventy-two million, fifty-one thousand, six hundred eighty-one".