681194791 has 2 divisors, whose sum is σ = 681194792. Its totient is φ = 681194790.

The previous prime is 681194779. The next prime is 681194893. The reversal of 681194791 is 197491186.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 681194791 - 2⁷ = 681194663 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (681194741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340597395 + 340597396.

It is an arithmetic number, because the mean of its divisors is an integer number (340597396).

Almost surely, 2^681194791 is an apocalyptic number.

681194791 is a deficient number, since it is larger than the sum of its proper divisors (1).

681194791 is an equidigital number, since it uses as much as digits as its factorization.

681194791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 46.

The square root of 681194791 is about 26099.7086382205. The cubic root of 681194791 is about 879.8806617613.

The spelling of 681194791 in words is "six hundred eighty-one million, one hundred ninety-four thousand, seven hundred ninety-one".