21312513201 has 16 divisors (see below), whose sum is σ = 33138992000. Its totient is φ = 12178578384.

The previous prime is 21312513197. The next prime is 21312513239. The reversal of 21312513201 is 10231521312.

It is not a de Polignac number, because 21312513201 - 2² = 21312513197 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21312513241) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 10354906 + ... + 10356963.

It is an arithmetic number, because the mean of its divisors is an integer number (2071187000).

Almost surely, 2^21312513201 is an apocalyptic number.

21312513201 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21312513201 is a deficient number, since it is larger than the sum of its proper divisors (11826478799).

21312513201 is an equidigital number, since it uses as much as digits as its factorization.

21312513201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20711893 (or 20711879 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 21.

The spelling of 21312513201 in words is "twenty-one billion, three hundred twelve million, five hundred thirteen thousand, two hundred one".