61312509977 has 2 divisors, whose sum is σ = 61312509978. Its totient is φ = 61312509976.

The previous prime is 61312509917. The next prime is 61312510003. The reversal of 61312509977 is 77990521316.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35591086336 + 25721423641 = 188656^2 + 160379^2 .

It is a cyclic number.

It is not a de Polignac number, because 61312509977 - 2⁸ = 61312509721 is a prime.

It is not a weakly prime, because it can be changed into another prime (61312509917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30656254988 + 30656254989.

It is an arithmetic number, because the mean of its divisors is an integer number (30656254989).

Almost surely, 2^61312509977 is an apocalyptic number.

It is an amenable number.

61312509977 is a deficient number, since it is larger than the sum of its proper divisors (1).

61312509977 is an equidigital number, since it uses as much as digits as its factorization.

61312509977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 714420, while the sum is 50.

The spelling of 61312509977 in words is "sixty-one billion, three hundred twelve million, five hundred nine thousand, nine hundred seventy-seven".