21202110100 has 36 divisors (see below), whose sum is σ = 46121158300. Its totient is φ = 8460092160.

The previous prime is 21202110077. The next prime is 21202110103. The reversal of 21202110100 is 101120212.

It can be written as a sum of positive squares in 6 ways, for example, as 751966084 + 20450144016 = 27422^2 + 143004^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202110103) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 218295 + ... + 300094.

Almost surely, 2^21202110100 is an apocalyptic number.

21202110100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202110100 is an abundant number, since it is smaller than the sum of its proper divisors (24919048200).

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

21202110100 is a wasteful number, since it uses less digits than its factorization.

21202110100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 518812 (or 518805 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21202110100 its reverse (101120212), we get a palindrome (21303230312).

The spelling of 21202110100 in words is "twenty-one billion, two hundred two million, one hundred ten thousand, one hundred".