20645672100 has 72 divisors (see below), whose sum is σ = 63248639328. Its totient is φ = 5181657600.

The previous prime is 20645672063. The next prime is 20645672153. The reversal of 20645672100 is 127654602.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2018986 + ... + 2029185.

It is an arithmetic number, because the mean of its divisors is an integer number (878453324).

Almost surely, 2^20645672100 is an apocalyptic number.

20645672100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20645672100 is an abundant number, since it is smaller than the sum of its proper divisors (42602967228).

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

20645672100 is a wasteful number, since it uses less digits than its factorization.

20645672100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4048205 (or 4048198 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 33.

The spelling of 20645672100 in words is "twenty billion, six hundred forty-five million, six hundred seventy-two thousand, one hundred".