7777421857697 has 2 divisors, whose sum is σ = 7777421857698. Its totient is φ = 7777421857696.

The previous prime is 7777421857691. The next prime is 7777421857721. The reversal of 7777421857697 is 7967581247777.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6455253036961 + 1322168820736 = 2540719^2 + 1149856^2 .

It is a cyclic number.

It is not a de Polignac number, because 7777421857697 - 2¹⁸ = 7777421595553 is a prime.

It is not a weakly prime, because it can be changed into another prime (7777421857691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3888710928848 + 3888710928849.

It is an arithmetic number, because the mean of its divisors is an integer number (3888710928849).

Almost surely, 2^{7777421857697} is an apocalyptic number.

It is an amenable number.

7777421857697 is a deficient number, since it is larger than the sum of its proper divisors (1).

7777421857697 is an equidigital number, since it uses as much as digits as its factorization.

7777421857697 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2032974720, while the sum is 77.

The spelling of 7777421857697 in words is "seven trillion, seven hundred seventy-seven billion, four hundred twenty-one million, eight hundred fifty-seven thousand, six hundred ninety-seven".