669889057 has 2 divisors, whose sum is σ = 669889058. Its totient is φ = 669889056.

The previous prime is 669889019. The next prime is 669889091. The reversal of 669889057 is 750988966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 365421456 + 304467601 = 19116^2 + 17449^2 .

It is a cyclic number.

It is not a de Polignac number, because 669889057 - 2¹⁵ = 669856289 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 669888992 and 669889010.

It is not a weakly prime, because it can be changed into another prime (669809057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334944528 + 334944529.

It is an arithmetic number, because the mean of its divisors is an integer number (334944529).

Almost surely, 2^669889057 is an apocalyptic number.

It is an amenable number.

669889057 is a deficient number, since it is larger than the sum of its proper divisors (1).

669889057 is an equidigital number, since it uses as much as digits as its factorization.

669889057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6531840, while the sum is 58.

The square root of 669889057 is about 25882.2150713574. The cubic root of 669889057 is about 874.9857116578.

The spelling of 669889057 in words is "six hundred sixty-nine million, eight hundred eighty-nine thousand, fifty-seven".