72715521 has 8 divisors (see below), whose sum is σ = 97176640. Its totient is φ = 48365712.

The previous prime is 72715507. The next prime is 72715549. The reversal of 72715521 is 12551727.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 72715521 - 2⁶ = 72715457 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (72715571) 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, 26290 + ... + 28923.

It is an arithmetic number, because the mean of its divisors is an integer number (12147080).

Almost surely, 2^72715521 is an apocalyptic number.

It is an amenable number.

72715521 is a deficient number, since it is larger than the sum of its proper divisors (24461119).

72715521 is a wasteful number, since it uses less digits than its factorization.

72715521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55655.

The product of its digits is 4900, while the sum is 30.

The square root of 72715521 is about 8527.3396203036. The cubic root of 72715521 is about 417.3903205503.

The spelling of 72715521 in words is "seventy-two million, seven hundred fifteen thousand, five hundred twenty-one".