668768077 has 2 divisors, whose sum is σ = 668768078. Its totient is φ = 668768076.

The previous prime is 668768069. The next prime is 668768129. The reversal of 668768077 is 770867866.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 540376516 + 128391561 = 23246^2 + 11331^2 .

It is a cyclic number.

It is not a de Polignac number, because 668768077 - 2³ = 668768069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668768047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334384038 + 334384039.

It is an arithmetic number, because the mean of its divisors is an integer number (334384039).

Almost surely, 2^668768077 is an apocalyptic number.

It is an amenable number.

668768077 is a deficient number, since it is larger than the sum of its proper divisors (1).

668768077 is an equidigital number, since it uses as much as digits as its factorization.

668768077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4741632, while the sum is 55.

The square root of 668768077 is about 25860.5505935199. The cubic root of 668768077 is about 874.4973775129.

The spelling of 668768077 in words is "six hundred sixty-eight million, seven hundred sixty-eight thousand, seventy-seven".