31988986 has 4 divisors (see below), whose sum is σ = 47983482. Its totient is φ = 15994492.

The previous prime is 31988981. The next prime is 31988987. The reversal of 31988986 is 68988913.

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

It can be written as a sum of positive squares in only one way, i.e., 19633761 + 12355225 = 4431^2 + 3515^2 .

It is not an unprimeable number, because it can be changed into a prime (31988981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7997245 + ... + 7997248.

Almost surely, 2^31988986 is an apocalyptic number.

31988986 is a deficient number, since it is larger than the sum of its proper divisors (15994496).

31988986 is a wasteful number, since it uses less digits than its factorization.

31988986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15994495.

The product of its digits is 746496, while the sum is 52.

The square root of 31988986 is about 5655.8806564495. The cubic root of 31988986 is about 317.4437819739.

The spelling of 31988986 in words is "thirty-one million, nine hundred eighty-eight thousand, nine hundred eighty-six".