21312131013 has 24 divisors (see below), whose sum is σ = 31062208320. Its totient is φ = 14080073280.

The previous prime is 21312130999. The next prime is 21312131047. The reversal of 21312131013 is 31013121312.

It is not a de Polignac number, because 21312131013 - 2⁴ = 21312130997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312131053) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 863833 + ... + 888161.

It is an arithmetic number, because the mean of its divisors is an integer number (1294258680).

Almost surely, 2^21312131013 is an apocalyptic number.

It is an amenable number.

21312131013 is a deficient number, since it is larger than the sum of its proper divisors (9750077307).

21312131013 is a wasteful number, since it uses less digits than its factorization.

21312131013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25209 (or 25206 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 21312131013 its reverse (31013121312), we get a palindrome (52325252325).

The spelling of 21312131013 in words is "twenty-one billion, three hundred twelve million, one hundred thirty-one thousand, thirteen".