31397137 has 4 divisors (see below), whose sum is σ = 31572720. Its totient is φ = 31221556.

The previous prime is 31397129. The next prime is 31397143. The reversal of 31397137 is 73179313.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31397137 - 2³ = 31397129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31397167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87523 + ... + 87880.

It is an arithmetic number, because the mean of its divisors is an integer number (7893180).

Almost surely, 2^31397137 is an apocalyptic number.

It is an amenable number.

31397137 is a deficient number, since it is larger than the sum of its proper divisors (175583).

31397137 is a wasteful number, since it uses less digits than its factorization.

31397137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175582.

The product of its digits is 11907, while the sum is 34.

The square root of 31397137 is about 5603.3148224957. The cubic root of 31397137 is about 315.4738379774.

The spelling of 31397137 in words is "thirty-one million, three hundred ninety-seven thousand, one hundred thirty-seven".