20431368137 has 2 divisors, whose sum is σ = 20431368138. Its totient is φ = 20431368136.

The previous prime is 20431368103. The next prime is 20431368149. The reversal of 20431368137 is 73186313402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13433041801 + 6998326336 = 115901^2 + 83656^2 .

It is a cyclic number.

It is not a de Polignac number, because 20431368137 - 2²⁰ = 20430319561 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20431368137.

It is not a weakly prime, because it can be changed into another prime (20431368157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10215684068 + 10215684069.

It is an arithmetic number, because the mean of its divisors is an integer number (10215684069).

Almost surely, 2^20431368137 is an apocalyptic number.

It is an amenable number.

20431368137 is a deficient number, since it is larger than the sum of its proper divisors (1).

20431368137 is an equidigital number, since it uses as much as digits as its factorization.

20431368137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 38.

The spelling of 20431368137 in words is "twenty billion, four hundred thirty-one million, three hundred sixty-eight thousand, one hundred thirty-seven".