20131312997 has 2 divisors, whose sum is σ = 20131312998. Its totient is φ = 20131312996.

The previous prime is 20131312969. The next prime is 20131313047. The reversal of 20131312997 is 79921313102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20122557316 + 8755681 = 141854^2 + 2959^2 .

It is a cyclic number.

It is not a de Polignac number, because 20131312997 - 2¹⁸ = 20131050853 is a prime.

It is a super-2 number, since 2×20131312997² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20131312997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20131312897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10065656498 + 10065656499.

It is an arithmetic number, because the mean of its divisors is an integer number (10065656499).

Almost surely, 2^20131312997 is an apocalyptic number.

It is an amenable number.

20131312997 is a deficient number, since it is larger than the sum of its proper divisors (1).

20131312997 is an equidigital number, since it uses as much as digits as its factorization.

20131312997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20412, while the sum is 38.

The spelling of 20131312997 in words is "twenty billion, one hundred thirty-one million, three hundred twelve thousand, nine hundred ninety-seven".