72308531 has 4 divisors (see below), whose sum is σ = 76561992. Its totient is φ = 68055072.

The previous prime is 72308503. The next prime is 72308539. The reversal of 72308531 is 13580327.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 72308531 - 2¹⁰ = 72307507 is a prime.

It is a super-2 number, since 2×72308531² = 10457047310755922, 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 = 72308494 and 72308503.

It is not an unprimeable number, because it can be changed into a prime (72308539) 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, 2126705 + ... + 2126738.

It is an arithmetic number, because the mean of its divisors is an integer number (19140498).

Almost surely, 2^72308531 is an apocalyptic number.

72308531 is a deficient number, since it is larger than the sum of its proper divisors (4253461).

72308531 is a wasteful number, since it uses less digits than its factorization.

72308531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4253460.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 72308531 is about 8503.4423029735. The cubic root of 72308531 is about 416.6101496321.

Adding to 72308531 its reverse (13580327), we get a palindrome (85888858).

The spelling of 72308531 in words is "seventy-two million, three hundred eight thousand, five hundred thirty-one".