77712961 has 2 divisors, whose sum is σ = 77712962. Its totient is φ = 77712960.

The previous prime is 77712857. The next prime is 77712977. The reversal of 77712961 is 16921777.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77000625 + 712336 = 8775^2 + 844^2 .

It is a cyclic number.

It is not a de Polignac number, because 77712961 - 2¹⁹ = 77188673 is a prime.

It is not a weakly prime, because it can be changed into another prime (77712461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38856480 + 38856481.

It is an arithmetic number, because the mean of its divisors is an integer number (38856481).

Almost surely, 2^77712961 is an apocalyptic number.

It is an amenable number.

77712961 is a deficient number, since it is larger than the sum of its proper divisors (1).

77712961 is an equidigital number, since it uses as much as digits as its factorization.

77712961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37044, while the sum is 40.

The square root of 77712961 is about 8815.4955050751. The cubic root of 77712961 is about 426.7411129726.

The spelling of 77712961 in words is "seventy-seven million, seven hundred twelve thousand, nine hundred sixty-one".