77427808961 has 2 divisors, whose sum is σ = 77427808962. Its totient is φ = 77427808960.

The previous prime is 77427808943. The next prime is 77427809057. The reversal of 77427808961 is 16980872477.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65270541361 + 12157267600 = 255481^2 + 110260^2 .

It is a cyclic number.

It is not a de Polignac number, because 77427808961 - 2³⁰ = 76354067137 is a prime.

It is a super-2 number, since 2×77427808961² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 77427808961.

It is not a weakly prime, because it can be changed into another prime (77427858961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38713904480 + 38713904481.

It is an arithmetic number, because the mean of its divisors is an integer number (38713904481).

Almost surely, 2^77427808961 is an apocalyptic number.

It is an amenable number.

77427808961 is a deficient number, since it is larger than the sum of its proper divisors (1).

77427808961 is an equidigital number, since it uses as much as digits as its factorization.

77427808961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9483264, while the sum is 59.

The spelling of 77427808961 in words is "seventy-seven billion, four hundred twenty-seven million, eight hundred eight thousand, nine hundred sixty-one".