77897026249961 has 2 divisors, whose sum is σ = 77897026249962. Its totient is φ = 77897026249960.

The previous prime is 77897026249901. The next prime is 77897026249967. The reversal of 77897026249961 is 16994262079877.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77612223648400 + 284802601561 = 8809780^2 + 533669^2 .

It is a cyclic number.

It is not a de Polignac number, because 77897026249961 - 2³⁸ = 77622148343017 is a prime.

It is a super-2 number, since 2×77897026249961² (a number of 29 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (77897026249967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38948513124980 + 38948513124981.

It is an arithmetic number, because the mean of its divisors is an integer number (38948513124981).

Almost surely, 2^{77897026249961} is an apocalyptic number.

It is an amenable number.

77897026249961 is a deficient number, since it is larger than the sum of its proper divisors (1).

77897026249961 is an equidigital number, since it uses as much as digits as its factorization.

77897026249961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152216576, while the sum is 77.

The spelling of 77897026249961 in words is "seventy-seven trillion, eight hundred ninety-seven billion, twenty-six million, two hundred forty-nine thousand, nine hundred sixty-one".