21200100020 has 48 divisors (see below), whose sum is σ = 48769148736. Its totient is φ = 7677120000.

The previous prime is 21200099993. The next prime is 21200100023. The reversal of 21200100020 is 2000100212.

It is a junction number, because it is equal to n+sod(n) for n = 21200099980 and 21200100007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200100023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 146906 + ... + 252945.

It is an arithmetic number, because the mean of its divisors is an integer number (1016023932).

Almost surely, 2^21200100020 is an apocalyptic number.

21200100020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21200100020 is an abundant number, since it is smaller than the sum of its proper divisors (27569048716).

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

21200100020 is a wasteful number, since it uses less digits than its factorization.

21200100020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400112 (or 400110 counting only the distinct ones).

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

Adding to 21200100020 its reverse (2000100212), we get a palindrome (23200200232).

The spelling of 21200100020 in words is "twenty-one billion, two hundred million, one hundred thousand, twenty".