21012321200137 has 2 divisors, whose sum is σ = 21012321200138. Its totient is φ = 21012321200136.

The previous prime is 21012321200077. The next prime is 21012321200153. The reversal of 21012321200137 is 73100212321012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18392338699641 + 2619982500496 = 4288629^2 + 1618636^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012321200137 - 2¹⁹ = 21012320675849 is a prime.

It is not a weakly prime, because it can be changed into another prime (21012321200197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506160600068 + 10506160600069.

It is an arithmetic number, because the mean of its divisors is an integer number (10506160600069).

Almost surely, 2^{21012321200137} is an apocalyptic number.

It is an amenable number.

21012321200137 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012321200137 is an equidigital number, since it uses as much as digits as its factorization.

21012321200137 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 25.

Adding to 21012321200137 its reverse (73100212321012), we get a palindrome (94112533521149).

The spelling of 21012321200137 in words is "twenty-one trillion, twelve billion, three hundred twenty-one million, two hundred thousand, one hundred thirty-seven".