31618018 has 4 divisors (see below), whose sum is σ = 47427030. Its totient is φ = 15809008.

The previous prime is 31618003. The next prime is 31618043. The reversal of 31618018 is 81081613.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81081613 = 8543 ⋅9491.

It can be written as a sum of positive squares in only one way, i.e., 24235929 + 7382089 = 4923^2 + 2717^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7904503 + ... + 7904506.

Almost surely, 2^31618018 is an apocalyptic number.

31618018 is a deficient number, since it is larger than the sum of its proper divisors (15809012).

31618018 is a wasteful number, since it uses less digits than its factorization.

31618018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15809011.

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 31618018 is about 5622.9901298153. The cubic root of 31618018 is about 316.2119032155.

The spelling of 31618018 in words is "thirty-one million, six hundred eighteen thousand, eighteen".