20651572220 has 24 divisors (see below), whose sum is σ = 44863761600. Its totient is φ = 7975779392.

The previous prime is 20651572199. The next prime is 20651572223. The reversal of 20651572220 is 2227515602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20651572223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17802500 + ... + 17803659.

It is an arithmetic number, because the mean of its divisors is an integer number (1869323400).

Almost surely, 2^20651572220 is an apocalyptic number.

20651572220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20651572220 is an abundant number, since it is smaller than the sum of its proper divisors (24212189380).

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

20651572220 is a wasteful number, since it uses less digits than its factorization.

20651572220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35606197 (or 35606195 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 32.

The spelling of 20651572220 in words is "twenty billion, six hundred fifty-one million, five hundred seventy-two thousand, two hundred twenty".