21031200020 has 48 divisors (see below), whose sum is σ = 44377901568. Its totient is φ = 8372094720.

The previous prime is 21031200019. The next prime is 21031200061. The reversal of 21031200020 is 2000213012.

It is a happy number.

It is a super-2 number, since 2×21031200020² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21031199974 and 21031200010.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9840392 + ... + 9842528.

It is an arithmetic number, because the mean of its divisors is an integer number (924539616).

Almost surely, 2^21031200020 is an apocalyptic number.

21031200020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21031200020 is an abundant number, since it is smaller than the sum of its proper divisors (23346701548).

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

21031200020 is a wasteful number, since it uses less digits than its factorization.

21031200020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4280 (or 4278 counting only the distinct ones).

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

Adding to 21031200020 its reverse (2000213012), we get a palindrome (23031413032).

The spelling of 21031200020 in words is "twenty-one billion, thirty-one million, two hundred thousand, twenty".