31393131 has 32 divisors (see below), whose sum is σ = 53611008. Its totient is φ = 15863040.

The previous prime is 31393129. The next prime is 31393151. The reversal of 31393131 is 13139313.

It is not a de Polignac number, because 31393131 - 2¹ = 31393129 is a prime.

It is a super-2 number, since 2×31393131² = 1971057347966322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31393121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6711 + ... + 10383.

It is an arithmetic number, because the mean of its divisors is an integer number (1675344).

Almost surely, 2^31393131 is an apocalyptic number.

31393131 is a deficient number, since it is larger than the sum of its proper divisors (22217877).

31393131 is a wasteful number, since it uses less digits than its factorization.

31393131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3731.

The product of its digits is 729, while the sum is 24.

The square root of 31393131 is about 5602.9573441175. The cubic root of 31393131 is about 315.4604201728.

The spelling of 31393131 in words is "thirty-one million, three hundred ninety-three thousand, one hundred thirty-one".