20055566172 has 12 divisors (see below), whose sum is σ = 46796321096. Its totient is φ = 6685188720.

The previous prime is 20055566171. The next prime is 20055566189. The reversal of 20055566172 is 27166555002.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 20055566172.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20055566171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 835648579 + ... + 835648602.

Almost surely, 2^20055566172 is an apocalyptic number.

It is an amenable number.

20055566172 is an abundant number, since it is smaller than the sum of its proper divisors (26740754924).

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

20055566172 is a wasteful number, since it uses less digits than its factorization.

20055566172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1671297188 (or 1671297186 counting only the distinct ones).

The product of its (nonzero) digits is 126000, while the sum is 39.

The spelling of 20055566172 in words is "twenty billion, fifty-five million, five hundred sixty-six thousand, one hundred seventy-two".