20218986 has 24 divisors (see below), whose sum is σ = 44877924. Its totient is φ = 6575040.

The previous prime is 20218973. The next prime is 20218993. The reversal of 20218986 is 68981202.

It can be written as a sum of positive squares in 2 ways, for example, as 19633761 + 585225 = 4431^2 + 765^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20218986.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12961 + ... + 14436.

Almost surely, 2^20218986 is an apocalyptic number.

20218986 is an abundant number, since it is smaller than the sum of its proper divisors (24658938).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20218986 is a wasteful number, since it uses less digits than its factorization.

20218986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27446 (or 27443 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 20218986 is about 4496.5526795535. The cubic root of 20218986 is about 272.4288667682.

The spelling of 20218986 in words is "twenty million, two hundred eighteen thousand, nine hundred eighty-six".