669966677 has 2 divisors, whose sum is σ = 669966678. Its totient is φ = 669966676.

The previous prime is 669966667. The next prime is 669966679. The reversal of 669966677 is 776669966.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 669722641 + 244036 = 25879^2 + 494^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-669966677 is a prime.

Together with 669966679, it forms a pair of twin primes.

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 (669966679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334983338 + 334983339.

It is an arithmetic number, because the mean of its divisors is an integer number (334983339).

Almost surely, 2^669966677 is an apocalyptic number.

It is an amenable number.

669966677 is a deficient number, since it is larger than the sum of its proper divisors (1).

669966677 is an equidigital number, since it uses as much as digits as its factorization.

669966677 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30862944, while the sum is 62.

The square root of 669966677 is about 25883.7145131838. The cubic root of 669966677 is about 875.0195051978.

The spelling of 669966677 in words is "six hundred sixty-nine million, nine hundred sixty-six thousand, six hundred seventy-seven".