77161661 has 2 divisors, whose sum is σ = 77161662. Its totient is φ = 77161660.

The previous prime is 77161627. The next prime is 77161703. The reversal of 77161661 is 16616177.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 45024100 + 32137561 = 6710^2 + 5669^2 .

It is an emirp because it is prime and its reverse (16616177) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77161661 - 2⁶ = 77161597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77161621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38580830 + 38580831.

It is an arithmetic number, because the mean of its divisors is an integer number (38580831).

Almost surely, 2^77161661 is an apocalyptic number.

It is an amenable number.

77161661 is a deficient number, since it is larger than the sum of its proper divisors (1).

77161661 is an equidigital number, since it uses as much as digits as its factorization.

77161661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10584, while the sum is 35.

The square root of 77161661 is about 8784.1710479703. The cubic root of 77161661 is about 425.7296090274.

The spelling of 77161661 in words is "seventy-seven million, one hundred sixty-one thousand, six hundred sixty-one".