72905521 has 8 divisors (see below), whose sum is σ = 81046784. Its totient is φ = 65126160.

The previous prime is 72905519. The next prime is 72905531. The reversal of 72905521 is 12550927.

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 72905521 - 2¹ = 72905519 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is not an unprimeable number, because it can be changed into a prime (72905501) 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, 90051 + ... + 90856.

It is an arithmetic number, because the mean of its divisors is an integer number (10130848).

Almost surely, 2^72905521 is an apocalyptic number.

It is an amenable number.

72905521 is a deficient number, since it is larger than the sum of its proper divisors (8141263).

72905521 is a wasteful number, since it uses less digits than its factorization.

72905521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180951.

The product of its (nonzero) digits is 6300, while the sum is 31.

The square root of 72905521 is about 8538.4729899438. The cubic root of 72905521 is about 417.7535405252.

The spelling of 72905521 in words is "seventy-two million, nine hundred five thousand, five hundred twenty-one".