31688745 has 16 divisors (see below), whose sum is σ = 55311552. Its totient is φ = 15364160.

The previous prime is 31688743. The next prime is 31688747. The reversal of 31688745 is 54788613.

It is an interprime number because it is at equal distance from previous prime (31688743) and next prime (31688747).

It is not a de Polignac number, because 31688745 - 2¹ = 31688743 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31688697 and 31688706.

It is not an unprimeable number, because it can be changed into a prime (31688743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 95862 + ... + 96191.

It is an arithmetic number, because the mean of its divisors is an integer number (3456972).

Almost surely, 2^31688745 is an apocalyptic number.

It is an amenable number.

31688745 is a deficient number, since it is larger than the sum of its proper divisors (23622807).

31688745 is a wasteful number, since it uses less digits than its factorization.

31688745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192072.

The product of its digits is 161280, while the sum is 42.

The square root of 31688745 is about 5629.2757082950. The cubic root of 31688745 is about 316.4475079472.

The spelling of 31688745 in words is "thirty-one million, six hundred eighty-eight thousand, seven hundred forty-five".