77380661 has 2 divisors, whose sum is σ = 77380662. Its totient is φ = 77380660.

The previous prime is 77380643. The next prime is 77380669. The reversal of 77380661 is 16608377.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77334436 + 46225 = 8794^2 + 215^2 .

It is an emirp because it is prime and its reverse (16608377) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77380661 - 2¹⁰ = 77379637 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77380669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38690330 + 38690331.

It is an arithmetic number, because the mean of its divisors is an integer number (38690331).

Almost surely, 2^77380661 is an apocalyptic number.

It is an amenable number.

77380661 is a deficient number, since it is larger than the sum of its proper divisors (1).

77380661 is an equidigital number, since it uses as much as digits as its factorization.

77380661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42336, while the sum is 38.

The square root of 77380661 is about 8796.6278197955. The cubic root of 77380661 is about 426.1319967579.

The spelling of 77380661 in words is "seventy-seven million, three hundred eighty thousand, six hundred sixty-one".