72857231 has 4 divisors (see below), whose sum is σ = 72880992. Its totient is φ = 72833472.

The previous prime is 72857221. The next prime is 72857237. The reversal of 72857231 is 13275827.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13275827 = 17 ⋅780931.

It is a cyclic number.

It is not a de Polignac number, because 72857231 - 2²² = 68662927 is a prime.

It is a super-2 number, since 2×72857231² = 10616352217974722, 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 = 72857191 and 72857200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72857237) 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, 6455 + ... + 13688.

It is an arithmetic number, because the mean of its divisors is an integer number (18220248).

Almost surely, 2^72857231 is an apocalyptic number.

72857231 is a deficient number, since it is larger than the sum of its proper divisors (23761).

72857231 is a wasteful number, since it uses less digits than its factorization.

72857231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23760.

The product of its digits is 23520, while the sum is 35.

The square root of 72857231 is about 8535.6447325319. The cubic root of 72857231 is about 417.6612851703.

The spelling of 72857231 in words is "seventy-two million, eight hundred fifty-seven thousand, two hundred thirty-one".