21312013123120 has 40 divisors (see below), whose sum is σ = 49551052279680. Its totient is φ = 8524698278400.

The previous prime is 21312013123103. The next prime is 21312013123127. The reversal of 21312013123120 is 2132131021312.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 21312013123091 and 21312013123100.

It is not an unprimeable number, because it can be changed into a prime (21312013123127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4904545 + ... + 8165695.

It is an arithmetic number, because the mean of its divisors is an integer number (1238776306992).

Almost surely, 2^{21312013123120} is an apocalyptic number.

21312013123120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21312013123120 is an abundant number, since it is smaller than the sum of its proper divisors (28239039156560).

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

21312013123120 is a wasteful number, since it uses less digits than its factorization.

21312013123120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3342853 (or 3342847 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

Adding to 21312013123120 its reverse (2132131021312), we get a palindrome (23444144144432).

The spelling of 21312013123120 in words is "twenty-one trillion, three hundred twelve billion, thirteen million, one hundred twenty-three thousand, one hundred twenty".