21321023105020 has 48 divisors (see below), whose sum is σ = 45106204340736. Its totient is φ = 8465354240000.

The previous prime is 21321023105009. The next prime is 21321023105069. The reversal of 21321023105020 is 2050132012312.

It is a junction number, because it is equal to n+sod(n) for n = 21321023104982 and 21321023105000.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4292581 + ... + 7814620.

It is an arithmetic number, because the mean of its divisors is an integer number (939712590432).

Almost surely, 2^{21321023105020} is an apocalyptic number.

21321023105020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21321023105020 is an abundant number, since it is smaller than the sum of its proper divisors (23785181235716).

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

21321023105020 is a wasteful number, since it uses less digits than its factorization.

21321023105020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12107862 (or 12107860 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

Adding to 21321023105020 its reverse (2050132012312), we get a palindrome (23371155117332).

The spelling of 21321023105020 in words is "twenty-one trillion, three hundred twenty-one billion, twenty-three million, one hundred five thousand, twenty".