20510550172 has 24 divisors (see below), whose sum is σ = 41025670784. Its totient is φ = 8789256432.

The previous prime is 20510550157. The next prime is 20510550197. The reversal of 20510550172 is 27105501502.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a self number, because there is not a number n which added to its sum of digits gives 20510550172.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 251803 + ... + 323149.

Almost surely, 2^20510550172 is an apocalyptic number.

It is an amenable number.

20510550172 is an abundant number, since it is smaller than the sum of its proper divisors (20515120612).

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

20510550172 is a wasteful number, since it uses less digits than its factorization.

20510550172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81625 (or 81623 counting only the distinct ones).

The product of its (nonzero) digits is 3500, while the sum is 28.

The spelling of 20510550172 in words is "twenty billion, five hundred ten million, five hundred fifty thousand, one hundred seventy-two".