78777404291 has 2 divisors, whose sum is σ = 78777404292. Its totient is φ = 78777404290.

The previous prime is 78777404281. The next prime is 78777404309. The reversal of 78777404291 is 19240477787.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78777404291 - 2⁶ = 78777404227 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (78777404281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39388702145 + 39388702146.

It is an arithmetic number, because the mean of its divisors is an integer number (39388702146).

Almost surely, 2^78777404291 is an apocalyptic number.

78777404291 is a deficient number, since it is larger than the sum of its proper divisors (1).

78777404291 is an equidigital number, since it uses as much as digits as its factorization.

78777404291 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5531904, while the sum is 56.

The spelling of 78777404291 in words is "seventy-eight billion, seven hundred seventy-seven million, four hundred four thousand, two hundred ninety-one".