2561176391 has 2 divisors, whose sum is σ = 2561176392. Its totient is φ = 2561176390.

The previous prime is 2561176337. The next prime is 2561176403. The reversal of 2561176391 is 1936711652.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2561176391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2561176091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1280588195 + 1280588196.

It is an arithmetic number, because the mean of its divisors is an integer number (1280588196).

Almost surely, 2^2561176391 is an apocalyptic number.

2561176391 is a deficient number, since it is larger than the sum of its proper divisors (1).

2561176391 is an equidigital number, since it uses as much as digits as its factorization.

2561176391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 68040, while the sum is 41.

The square root of 2561176391 is about 50608.0664617806. The cubic root of 2561176391 is about 1368.1902669522.

The spelling of 2561176391 in words is "two billion, five hundred sixty-one million, one hundred seventy-six thousand, three hundred ninety-one".