20555660 has 12 divisors (see below), whose sum is σ = 43166928. Its totient is φ = 8222256.

The previous prime is 20555651. The next prime is 20555681. The reversal of 20555660 is 6655502.

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 3 ways as a sum of consecutive naturals, for example, 513872 + ... + 513911.

It is an arithmetic number, because the mean of its divisors is an integer number (3597244).

Almost surely, 2^20555660 is an apocalyptic number.

20555660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20555660 is an abundant number, since it is smaller than the sum of its proper divisors (22611268).

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

20555660 is a wasteful number, since it uses less digits than its factorization.

20555660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1027792 (or 1027790 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 29.

The square root of 20555660 is about 4533.8350212596. The cubic root of 20555660 is about 273.9326561190.

The spelling of 20555660 in words is "twenty million, five hundred fifty-five thousand, six hundred sixty".