2597666891 has 2 divisors, whose sum is σ = 2597666892. Its totient is φ = 2597666890.

The previous prime is 2597666879. The next prime is 2597666921. The reversal of 2597666891 is 1986667952.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2597666891 - 2¹⁰ = 2597665867 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2597666891.

It is not a weakly prime, because it can be changed into another prime (2597666831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1298833445 + 1298833446.

It is an arithmetic number, because the mean of its divisors is an integer number (1298833446).

Almost surely, 2^2597666891 is an apocalyptic number.

2597666891 is a deficient number, since it is larger than the sum of its proper divisors (1).

2597666891 is an equidigital number, since it uses as much as digits as its factorization.

2597666891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9797760, while the sum is 59.

The square root of 2597666891 is about 50967.3119852323. The cubic root of 2597666891 is about 1374.6574381447.

The spelling of 2597666891 in words is "two billion, five hundred ninety-seven million, six hundred sixty-six thousand, eight hundred ninety-one".