72755681 has 4 divisors (see below), whose sum is σ = 72964500. Its totient is φ = 72546864.

The previous prime is 72755659. The next prime is 72755687. The reversal of 72755681 is 18655727.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 64000000 + 8755681 = 8000^2 + 2959^2 .

It is a cyclic number.

It is not a de Polignac number, because 72755681 - 2¹⁸ = 72493537 is a prime.

It is a super-2 number, since 2×72755681² = 10586778235547522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72755687) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 103886 + ... + 104583.

It is an arithmetic number, because the mean of its divisors is an integer number (18241125).

Almost surely, 2^72755681 is an apocalyptic number.

It is an amenable number.

72755681 is a deficient number, since it is larger than the sum of its proper divisors (208819).

72755681 is a wasteful number, since it uses less digits than its factorization.

72755681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208818.

The product of its digits is 117600, while the sum is 41.

The square root of 72755681 is about 8529.6940742327. The cubic root of 72755681 is about 417.4671464700.

The spelling of 72755681 in words is "seventy-two million, seven hundred fifty-five thousand, six hundred eighty-one".