20556984 has 32 divisors (see below), whose sum is σ = 58734720. Its totient is φ = 5873376.

The previous prime is 20556979. The next prime is 20557003. The reversal of 20556984 is 48965502.

It is a congruent number.

It is an unprimeable number.

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, 61014 + ... + 61349.

It is an arithmetic number, because the mean of its divisors is an integer number (1835460).

Almost surely, 2^20556984 is an apocalyptic number.

20556984 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20556984 is an abundant number, since it is smaller than the sum of its proper divisors (38177736).

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

20556984 is a wasteful number, since it uses less digits than its factorization.

20556984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122379 (or 122375 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 39.

The square root of 20556984 is about 4533.9810321615. The cubic root of 20556984 is about 273.9385373710.

The spelling of 20556984 in words is "twenty million, five hundred fifty-six thousand, nine hundred eighty-four".