77681968279 has 2 divisors, whose sum is σ = 77681968280. Its totient is φ = 77681968278.

The previous prime is 77681968241. The next prime is 77681968283. The reversal of 77681968279 is 97286918677.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 77681968279 - 2⁹ = 77681967767 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77681968289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38840984139 + 38840984140.

It is an arithmetic number, because the mean of its divisors is an integer number (38840984140).

Almost surely, 2^77681968279 is an apocalyptic number.

77681968279 is a deficient number, since it is larger than the sum of its proper divisors (1).

77681968279 is an equidigital number, since it uses as much as digits as its factorization.

77681968279 is an evil number, because the sum of its binary digits is even.

The product of its digits is 128024064, while the sum is 70.

The spelling of 77681968279 in words is "seventy-seven billion, six hundred eighty-one million, nine hundred sixty-eight thousand, two hundred seventy-nine".