231208731 has 36 divisors (see below), whose sum is σ = 366898896. Its totient is φ = 140212800.

The previous prime is 231208723. The next prime is 231208741. The reversal of 231208731 is 137802132.

It is not a de Polignac number, because 231208731 - 2³ = 231208723 is a prime.

It is a super-2 number, since 2×231208731² = 106914954581260722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 231208695 and 231208704.

It is not an unprimeable number, because it can be changed into a prime (231208711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 106921 + ... + 109061.

It is an arithmetic number, because the mean of its divisors is an integer number (10191636).

Almost surely, 2^231208731 is an apocalyptic number.

231208731 is a deficient number, since it is larger than the sum of its proper divisors (135690165).

231208731 is a wasteful number, since it uses less digits than its factorization.

231208731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2244 (or 2228 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 231208731 is about 15205.5493488397. The cubic root of 231208731 is about 613.7639978667.

The spelling of 231208731 in words is "two hundred thirty-one million, two hundred eight thousand, seven hundred thirty-one".