20556188 has 6 divisors (see below), whose sum is σ = 35973336. Its totient is φ = 10278092.

The previous prime is 20556161. The next prime is 20556191. The reversal of 20556188 is 88165502.

It is a happy number.

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 as a sum of consecutive naturals, namely, 2569520 + ... + 2569527.

It is an arithmetic number, because the mean of its divisors is an integer number (5995556).

Almost surely, 2^20556188 is an apocalyptic number.

It is an amenable number.

20556188 is a deficient number, since it is larger than the sum of its proper divisors (15417148).

20556188 is a wasteful number, since it uses less digits than its factorization.

20556188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5139051 (or 5139049 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 35.

The square root of 20556188 is about 4533.8932497358. The cubic root of 20556188 is about 273.9350015428.

The spelling of 20556188 in words is "twenty million, five hundred fifty-six thousand, one hundred eighty-eight".