77777122091 has 2 divisors, whose sum is σ = 77777122092. Its totient is φ = 77777122090.

The previous prime is 77777121979. The next prime is 77777122109. The reversal of 77777122091 is 19022177777.

Together with next prime (77777122109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is an emirp because it is prime and its reverse (19022177777) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77777122091 - 2¹⁰ = 77777121067 is a prime.

It is not a weakly prime, because it can be changed into another prime (77777172091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38888561045 + 38888561046.

It is an arithmetic number, because the mean of its divisors is an integer number (38888561046).

Almost surely, 2^77777122091 is an apocalyptic number.

77777122091 is a deficient number, since it is larger than the sum of its proper divisors (1).

77777122091 is an equidigital number, since it uses as much as digits as its factorization.

77777122091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 605052, while the sum is 50.

The spelling of 77777122091 in words is "seventy-seven billion, seven hundred seventy-seven million, one hundred twenty-two thousand, ninety-one".