776680991 has 2 divisors, whose sum is σ = 776680992. Its totient is φ = 776680990.

The previous prime is 776680967. The next prime is 776681021. The reversal of 776680991 is 199086677.

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-776680991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (776680691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 388340495 + 388340496.

It is an arithmetic number, because the mean of its divisors is an integer number (388340496).

Almost surely, 2^776680991 is an apocalyptic number.

776680991 is a deficient number, since it is larger than the sum of its proper divisors (1).

776680991 is an equidigital number, since it uses as much as digits as its factorization.

776680991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1143072, while the sum is 53.

The square root of 776680991 is about 27868.9969500160. The cubic root of 776680991 is about 919.2089099805.

The spelling of 776680991 in words is "seven hundred seventy-six million, six hundred eighty thousand, nine hundred ninety-one".