665556677 has 2 divisors, whose sum is σ = 665556678. Its totient is φ = 665556676.

The previous prime is 665556637. The next prime is 665556691. The reversal of 665556677 is 776655566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 572453476 + 93103201 = 23926^2 + 9649^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665556677 is a prime.

It is a Chen prime.

It is a zygodrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665556637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332778338 + 332778339.

It is an arithmetic number, because the mean of its divisors is an integer number (332778339).

Almost surely, 2^665556677 is an apocalyptic number.

It is an amenable number.

665556677 is a deficient number, since it is larger than the sum of its proper divisors (1).

665556677 is an equidigital number, since it uses as much as digits as its factorization.

665556677 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7938000, while the sum is 53.

The square root of 665556677 is about 25798.3851626415. The cubic root of 665556677 is about 873.0953627631.

The spelling of 665556677 in words is "six hundred sixty-five million, five hundred fifty-six thousand, six hundred seventy-seven".