77775252391 has 2 divisors, whose sum is σ = 77775252392. Its totient is φ = 77775252390.

The previous prime is 77775252389. The next prime is 77775252469. The reversal of 77775252391 is 19325257777.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 77775252391 - 2¹ = 77775252389 is a prime.

Together with 77775252389, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77775252371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38887626195 + 38887626196.

It is an arithmetic number, because the mean of its divisors is an integer number (38887626196).

Almost surely, 2^77775252391 is an apocalyptic number.

77775252391 is a deficient number, since it is larger than the sum of its proper divisors (1).

77775252391 is an equidigital number, since it uses as much as digits as its factorization.

77775252391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6482700, while the sum is 55.

The spelling of 77775252391 in words is "seventy-seven billion, seven hundred seventy-five million, two hundred fifty-two thousand, three hundred ninety-one".