31618989 has 6 divisors (see below), whose sum is σ = 45671886. Its totient is φ = 21079320.

The previous prime is 31618981. The next prime is 31618991. The reversal of 31618989 is 98981613.

It can be written as a sum of positive squares in only one way, i.e., 20629764 + 10989225 = 4542^2 + 3315^2 .

It is not a de Polignac number, because 31618989 - 2³ = 31618981 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31618981) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1756602 + ... + 1756619.

It is an arithmetic number, because the mean of its divisors is an integer number (7611981).

Almost surely, 2^31618989 is an apocalyptic number.

It is an amenable number.

31618989 is a deficient number, since it is larger than the sum of its proper divisors (14052897).

31618989 is a wasteful number, since it uses less digits than its factorization.

31618989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3513227 (or 3513224 counting only the distinct ones).

The product of its digits is 93312, while the sum is 45.

The square root of 31618989 is about 5623.0764711144. The cubic root of 31618989 is about 316.2151401738.

The spelling of 31618989 in words is "thirty-one million, six hundred eighteen thousand, nine hundred eighty-nine".