20210021100 has 72 divisors (see below), whose sum is σ = 64971483920. Its totient is φ = 5389338240.

The previous prime is 20210021059. The next prime is 20210021131. The reversal of 20210021100 is 112001202.

It is a Harshad number since it is a multiple of its sum of digits (9).

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, 3739897 + ... + 3745296.

Almost surely, 2^20210021100 is an apocalyptic number.

20210021100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20210021100 is an abundant number, since it is smaller than the sum of its proper divisors (44761462820).

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

20210021100 is a wasteful number, since it uses less digits than its factorization.

20210021100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7485216 (or 7485203 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 20210021100 its reverse (112001202), we get a palindrome (20322022302).

The spelling of 20210021100 in words is "twenty billion, two hundred ten million, twenty-one thousand, one hundred".