31886945 has 4 divisors (see below), whose sum is σ = 38264340. Its totient is φ = 25509552.

The previous prime is 31886929. The next prime is 31886983. The reversal of 31886945 is 54968813.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 25080064 + 6806881 = 5008^2 + 2609^2 .

It is a cyclic number.

It is not a de Polignac number, because 31886945 - 2⁴ = 31886929 is a prime.

It is a super-2 number, since 2×31886945² = 2033554522866050, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31886896 and 31886905.

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 3 ways as a sum of consecutive naturals, for example, 3188690 + ... + 3188699.

It is an arithmetic number, because the mean of its divisors is an integer number (9566085).

Almost surely, 2^31886945 is an apocalyptic number.

It is an amenable number.

31886945 is a deficient number, since it is larger than the sum of its proper divisors (6377395).

31886945 is an equidigital number, since it uses as much as digits as its factorization.

31886945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6377394.

The product of its digits is 207360, while the sum is 44.

The square root of 31886945 is about 5646.8526632098. The cubic root of 31886945 is about 317.1058866682.

The spelling of 31886945 in words is "thirty-one million, eight hundred eighty-six thousand, nine hundred forty-five".