77764011580781 has 2 divisors, whose sum is σ = 77764011580782. Its totient is φ = 77764011580780.

The previous prime is 77764011580669. The next prime is 77764011580873. The reversal of 77764011580781 is 18708511046777.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65154907715881 + 12609103864900 = 8071859^2 + 3550930^2 .

It is an emirp because it is prime and its reverse (18708511046777) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77764011580781 - 2¹⁰ = 77764011579757 is a prime.

It is a super-2 number, since 2×77764011580781² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77764011582781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38882005790390 + 38882005790391.

It is an arithmetic number, because the mean of its divisors is an integer number (38882005790391).

Almost surely, 2^{77764011580781} is an apocalyptic number.

It is an amenable number.

77764011580781 is a deficient number, since it is larger than the sum of its proper divisors (1).

77764011580781 is an equidigital number, since it uses as much as digits as its factorization.

77764011580781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18439680, while the sum is 62.

The spelling of 77764011580781 in words is "seventy-seven trillion, seven hundred sixty-four billion, eleven million, five hundred eighty thousand, seven hundred eighty-one".