72521431 has 8 divisors (see below), whose sum is σ = 77443200. Its totient is φ = 67761120.

The previous prime is 72521419. The next prime is 72521453. The reversal of 72521431 is 13412527.

It is a happy number.

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 72521431 - 2¹¹ = 72519383 is a prime.

It is a super-2 number, since 2×72521431² = 10518715908575522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72521396 and 72521405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72521401) 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, 39436 + ... + 41233.

It is an arithmetic number, because the mean of its divisors is an integer number (9680400).

Almost surely, 2^72521431 is an apocalyptic number.

72521431 is a deficient number, since it is larger than the sum of its proper divisors (4921769).

72521431 is a wasteful number, since it uses less digits than its factorization.

72521431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80729.

The product of its digits is 1680, while the sum is 25.

The square root of 72521431 is about 8515.9515616283. The cubic root of 72521431 is about 417.0186279099.

Adding to 72521431 its reverse (13412527), we get a palindrome (85933958).

The spelling of 72521431 in words is "seventy-two million, five hundred twenty-one thousand, four hundred thirty-one".