13378815997 has 2 divisors, whose sum is σ = 13378815998. Its totient is φ = 13378815996.

The previous prime is 13378815943. The next prime is 13378816037. The reversal of 13378815997 is 79951887331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13377004281 + 1811716 = 115659^2 + 1346^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13378815997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13378819997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6689407998 + 6689407999.

It is an arithmetic number, because the mean of its divisors is an integer number (6689407999).

Almost surely, 2^13378815997 is an apocalyptic number.

It is an amenable number.

13378815997 is a deficient number, since it is larger than the sum of its proper divisors (1).

13378815997 is an equidigital number, since it uses as much as digits as its factorization.

13378815997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11430720, while the sum is 61.

The spelling of 13378815997 in words is "thirteen billion, three hundred seventy-eight million, eight hundred fifteen thousand, nine hundred ninety-seven".