31618 has 4 divisors (see below), whose sum is σ = 47430. Its totient is φ = 15808.

The previous prime is 31607. The next prime is 31627. The reversal of 31618 is 81613.

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., 31329 + 289 = 177^2 + 17^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31595 and 31604.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7903 + ... + 7906.

2³¹⁶¹⁸ is an apocalyptic number.

31618 is a deficient number, since it is larger than the sum of its proper divisors (15812).

31618 is a wasteful number, since it uses less digits than its factorization.

31618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15811.

The product of its digits is 144, while the sum is 19.

The square root of 31618 is about 177.8145100941. The cubic root of 31618 is about 31.6211843209.

The spelling of 31618 in words is "thirty-one thousand, six hundred eighteen".