72508644 has 36 divisors (see below), whose sum is σ = 197385916. Its totient is φ = 22310208.

The previous prime is 72508619. The next prime is 72508651. The reversal of 72508644 is 44680527.

72508644 is a `hidden beast` number, since 7 + 2 + 5 + 0 + 8 + 644 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 46376100 + 26132544 = 6810^2 + 5112^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-3 number, since 3×72508644³ (a number of 25 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 72508599 and 72508608.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 76999 + ... + 77934.

Almost surely, 2^72508644 is an apocalyptic number.

It is an amenable number.

72508644 is an abundant number, since it is smaller than the sum of its proper divisors (124877272).

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

72508644 is a wasteful number, since it uses less digits than its factorization.

72508644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154956 (or 154951 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 72508644 is about 8515.2007609921. The cubic root of 72508644 is about 416.9941168537.

The spelling of 72508644 in words is "seventy-two million, five hundred eight thousand, six hundred forty-four".