20818986 has 16 divisors (see below), whose sum is σ = 41796000. Its totient is φ = 6913328.

The previous prime is 20818981. The next prime is 20818997. The reversal of 20818986 is 68981802.

It is not an unprimeable number, because it can be changed into a prime (20818981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4836 + ... + 8063.

It is an arithmetic number, because the mean of its divisors is an integer number (2612250).

Almost surely, 2^20818986 is an apocalyptic number.

20818986 is an abundant number, since it is smaller than the sum of its proper divisors (20977014).

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

20818986 is a wasteful number, since it uses less digits than its factorization.

20818986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13173.

The product of its (nonzero) digits is 55296, while the sum is 42.

The square root of 20818986 is about 4562.7827035703. The cubic root of 20818986 is about 275.0974244345.

The spelling of 20818986 in words is "twenty million, eight hundred eighteen thousand, nine hundred eighty-six".