20655660 has 48 divisors (see below), whose sum is σ = 60883200. Its totient is φ = 5217984.

The previous prime is 20655659. The next prime is 20655671. The reversal of 20655660 is 6655602.

It is a Harshad number since it is a multiple of its sum of digits (30).

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 15 ways as a sum of consecutive naturals, for example, 7920 + ... + 10199.

It is an arithmetic number, because the mean of its divisors is an integer number (1268400).

Almost surely, 2^20655660 is an apocalyptic number.

20655660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20655660 is an abundant number, since it is smaller than the sum of its proper divisors (40227540).

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

20655660 is a wasteful number, since it uses less digits than its factorization.

20655660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18150 (or 18148 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 30.

The square root of 20655660 is about 4544.8498325027. The cubic root of 20655660 is about 274.3761505790.

The spelling of 20655660 in words is "twenty million, six hundred fifty-five thousand, six hundred sixty".