72659521 has 4 divisors (see below), whose sum is σ = 79264944. Its totient is φ = 66054100.

The previous prime is 72659497. The next prime is 72659569. The reversal of 72659521 is 12595627.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12595627 = 11 ⋅1145057.

It is a cyclic number.

It is not a de Polignac number, because 72659521 - 2¹³ = 72651329 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72653521) 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, 3302695 + ... + 3302716.

It is an arithmetic number, because the mean of its divisors is an integer number (19816236).

Almost surely, 2^72659521 is an apocalyptic number.

It is an amenable number.

72659521 is a deficient number, since it is larger than the sum of its proper divisors (6605423).

72659521 is a wasteful number, since it uses less digits than its factorization.

72659521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6605422.

The product of its digits is 37800, while the sum is 37.

The square root of 72659521 is about 8524.0554315420. The cubic root of 72659521 is about 417.2831455371.

The spelling of 72659521 in words is "seventy-two million, six hundred fifty-nine thousand, five hundred twenty-one".