21131311200020 has 72 divisors (see below), whose sum is σ = 51622523355816. Its totient is φ = 7244775530496.

The previous prime is 21131311200019. The next prime is 21131311200049. The reversal of 21131311200020 is 2000211313112.

It can be written as a sum of positive squares in 4 ways, for example, as 1260239740816 + 19871071459204 = 1122604^2 + 4457698^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29850812 + ... + 30550508.

It is an arithmetic number, because the mean of its divisors is an integer number (716979491053).

Almost surely, 2^{21131311200020} is an apocalyptic number.

21131311200020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21131311200020 is an abundant number, since it is smaller than the sum of its proper divisors (30491212155796).

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

21131311200020 is a wasteful number, since it uses less digits than its factorization.

21131311200020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 730537 (or 730528 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 21131311200020 its reverse (2000211313112), we get a palindrome (23131522513132).

The spelling of 21131311200020 in words is "twenty-one trillion, one hundred thirty-one billion, three hundred eleven million, two hundred thousand, twenty".