15917378197 has 6 divisors (see below), whose sum is σ = 18516133878. Its totient is φ = 13643466984.

The previous prime is 15917378179. The next prime is 15917378227. The reversal of 15917378197 is 79187371951.

It can be written as a sum of positive squares in only one way, i.e., 10219996836 + 5697381361 = 101094^2 + 75481^2 .

It is not a de Polignac number, because 15917378197 - 2²⁷ = 15783160469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15917378167) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 162422178 + ... + 162422275.

It is an arithmetic number, because the mean of its divisors is an integer number (3086022313).

Almost surely, 2^15917378197 is an apocalyptic number.

It is an amenable number.

15917378197 is a deficient number, since it is larger than the sum of its proper divisors (2598755681).

15917378197 is an equidigital number, since it uses as much as digits as its factorization.

15917378197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324844467 (or 324844460 counting only the distinct ones).

The product of its digits is 3333960, while the sum is 58.

The spelling of 15917378197 in words is "fifteen billion, nine hundred seventeen million, three hundred seventy-eight thousand, one hundred ninety-seven".