72326521 has 4 divisors (see below), whose sum is σ = 76133200. Its totient is φ = 68519844.

The previous prime is 72326519. The next prime is 72326539. The reversal of 72326521 is 12562327.

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.

It is a cyclic number.

It is not a de Polignac number, because 72326521 - 2¹ = 72326519 is a prime.

It is a super-2 number, since 2×72326521² = 10462251279926882, which contains 22 as substring.

It is the 8505-th Hogben number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72326521.

It is not an unprimeable number, because it can be changed into a prime (72326581) by changing a digit.

It is a nontrivial repunit in base 8504.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1903311 + ... + 1903348.

It is an arithmetic number, because the mean of its divisors is an integer number (19033300).

Almost surely, 2^72326521 is an apocalyptic number.

It is an amenable number.

72326521 is a deficient number, since it is larger than the sum of its proper divisors (3806679).

72326521 is a wasteful number, since it uses less digits than its factorization.

72326521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3806678.

The product of its digits is 5040, while the sum is 28.

The square root of 72326521 is about 8504.5000440943. The cubic root of 72326521 is about 416.6446969394.

Adding to 72326521 its reverse (12562327), we get a palindrome (84888848).

The spelling of 72326521 in words is "seventy-two million, three hundred twenty-six thousand, five hundred twenty-one".