21321312198937 has 2 divisors, whose sum is σ = 21321312198938. Its totient is φ = 21321312198936.

The previous prime is 21321312198913. The next prime is 21321312198971. The reversal of 21321312198937 is 73989121312312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16519761931401 + 4801550267536 = 4064451^2 + 2191244^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21321312198937 is a prime.

It is not a weakly prime, because it can be changed into another prime (21321312118937) by changing a digit.

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 as a sum of consecutive naturals, namely, 10660656099468 + 10660656099469.

It is an arithmetic number, because the mean of its divisors is an integer number (10660656099469).

Almost surely, 2^{21321312198937} is an apocalyptic number.

It is an amenable number.

21321312198937 is a deficient number, since it is larger than the sum of its proper divisors (1).

21321312198937 is an equidigital number, since it uses as much as digits as its factorization.

21321312198937 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 979776, while the sum is 52.

The spelling of 21321312198937 in words is "twenty-one trillion, three hundred twenty-one billion, three hundred twelve million, one hundred ninety-eight thousand, nine hundred thirty-seven".