31393945 has 16 divisors (see below), whose sum is σ = 42211008. Its totient is φ = 22213440.

The previous prime is 31393937. The next prime is 31393981. The reversal of 31393945 is 54939313.

It is not a de Polignac number, because 31393945 - 2³ = 31393937 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 5679 + ... + 9748.

It is an arithmetic number, because the mean of its divisors is an integer number (2638188).

Almost surely, 2^31393945 is an apocalyptic number.

It is an amenable number.

31393945 is a deficient number, since it is larger than the sum of its proper divisors (10817063).

31393945 is a wasteful number, since it uses less digits than its factorization.

31393945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15480.

The product of its digits is 43740, while the sum is 37.

The square root of 31393945 is about 5603.0299838569. The cubic root of 31393945 is about 315.4631466988.

The spelling of 31393945 in words is "thirty-one million, three hundred ninety-three thousand, nine hundred forty-five".