77228820817 has 2 divisors, whose sum is σ = 77228820818. Its totient is φ = 77228820816.

The previous prime is 77228820727. The next prime is 77228820887. The reversal of 77228820817 is 71802882277.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74997108736 + 2231712081 = 273856^2 + 47241^2 .

It is a cyclic number.

It is not a de Polignac number, because 77228820817 - 2¹¹ = 77228818769 is a prime.

It is not a weakly prime, because it can be changed into another prime (77228820887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38614410408 + 38614410409.

It is an arithmetic number, because the mean of its divisors is an integer number (38614410409).

Almost surely, 2^77228820817 is an apocalyptic number.

It is an amenable number.

77228820817 is a deficient number, since it is larger than the sum of its proper divisors (1).

77228820817 is an equidigital number, since it uses as much as digits as its factorization.

77228820817 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1404928, while the sum is 52.

The spelling of 77228820817 in words is "seventy-seven billion, two hundred twenty-eight million, eight hundred twenty thousand, eight hundred seventeen".