72857831 has 4 divisors (see below), whose sum is σ = 75370200. Its totient is φ = 70345464.

The previous prime is 72857791. The next prime is 72857893. The reversal of 72857831 is 13875827.

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 72857831 - 2¹⁰ = 72856807 is a prime.

It is a super-2 number, since 2×72857831² = 10616527076049122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72857131) 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, 1256141 + ... + 1256198.

It is an arithmetic number, because the mean of its divisors is an integer number (18842550).

Almost surely, 2^72857831 is an apocalyptic number.

72857831 is a deficient number, since it is larger than the sum of its proper divisors (2512369).

72857831 is a wasteful number, since it uses less digits than its factorization.

72857831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2512368.

The product of its digits is 94080, while the sum is 41.

The square root of 72857831 is about 8535.6798791895. The cubic root of 72857831 is about 417.6624316869.

The spelling of 72857831 in words is "seventy-two million, eight hundred fifty-seven thousand, eight hundred thirty-one".