7957781791 has 2 divisors, whose sum is σ = 7957781792. Its totient is φ = 7957781790.

The previous prime is 7957781759. The next prime is 7957781807. The reversal of 7957781791 is 1971877597.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 7957781791 - 2⁵ = 7957781759 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7957781731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3978890895 + 3978890896.

It is an arithmetic number, because the mean of its divisors is an integer number (3978890896).

Almost surely, 2^7957781791 is an apocalyptic number.

7957781791 is a deficient number, since it is larger than the sum of its proper divisors (1).

7957781791 is an equidigital number, since it uses as much as digits as its factorization.

7957781791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7779240, while the sum is 61.

The square root of 7957781791 is about 89206.3999441744. The cubic root of 7957781791 is about 1996.4756088985.

The spelling of 7957781791 in words is "seven billion, nine hundred fifty-seven million, seven hundred eighty-one thousand, seven hundred ninety-one".