21020302100 has 72 divisors (see below), whose sum is σ = 52176118848. Its totient is φ = 7200633600.

The previous prime is 21020302063. The next prime is 21020302123. The reversal of 21020302100 is 120302012.

It is a happy number.

It is a congruent number.

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, 822515 + ... + 847685.

Almost surely, 2^21020302100 is an apocalyptic number.

21020302100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21020302100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26088059424).

21020302100 is an abundant number, since it is smaller than the sum of its proper divisors (31155816748).

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

21020302100 is a wasteful number, since it uses less digits than its factorization.

21020302100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26385 (or 26378 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

Adding to 21020302100 its reverse (120302012), we get a palindrome (21140604112).

The spelling of 21020302100 in words is "twenty-one billion, twenty million, three hundred two thousand, one hundred".