20986856 has 32 divisors (see below), whose sum is σ = 44798400. Its totient is φ = 9123840.

The previous prime is 20986853. The next prime is 20986859. The reversal of 20986856 is 65868902.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20986853) and next prime (20986859).

It is a Harshad number since it is a multiple of its sum of digits (44).

It is not an unprimeable number, because it can be changed into a prime (20986853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3161 + ... + 7208.

It is an arithmetic number, because the mean of its divisors is an integer number (1399950).

Almost surely, 2^20986856 is an apocalyptic number.

It is an amenable number.

20986856 is an abundant number, since it is smaller than the sum of its proper divisors (23811544).

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

20986856 is a wasteful number, since it uses less digits than its factorization.

20986856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10409 (or 10405 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 44.

The square root of 20986856 is about 4581.1413425041. The cubic root of 20986856 is about 275.8348448321.

The spelling of 20986856 in words is "twenty million, nine hundred eighty-six thousand, eight hundred fifty-six".