2161256579 has 2 divisors, whose sum is σ = 2161256580. Its totient is φ = 2161256578.

The previous prime is 2161256551. The next prime is 2161256611. The reversal of 2161256579 is 9756521612.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2161256579 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (2161256879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1080628289 + 1080628290.

It is an arithmetic number, because the mean of its divisors is an integer number (1080628290).

Almost surely, 2^2161256579 is an apocalyptic number.

2161256579 is a deficient number, since it is larger than the sum of its proper divisors (1).

2161256579 is an equidigital number, since it uses as much as digits as its factorization.

2161256579 is an evil number, because the sum of its binary digits is even.

The product of its digits is 226800, while the sum is 44.

The square root of 2161256579 is about 46489.3168265570. The cubic root of 2161256579 is about 1292.9114337028.

The spelling of 2161256579 in words is "two billion, one hundred sixty-one million, two hundred fifty-six thousand, five hundred seventy-nine".