669608649 has 12 divisors (see below), whose sum is σ = 998413312. Its totient is φ = 432005400.

The previous prime is 669608629. The next prime is 669608663. The reversal of 669608649 is 946806966.

It is a happy number.

It is not a de Polignac number, because 669608649 - 2²⁵ = 636054217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 669608595 and 669608604.

It is not an unprimeable number, because it can be changed into a prime (669608629) 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 in 11 ways as a sum of consecutive naturals, for example, 1199737 + ... + 1200294.

Almost surely, 2^669608649 is an apocalyptic number.

It is an amenable number.

669608649 is a deficient number, since it is larger than the sum of its proper divisors (328804663).

669608649 is a wasteful number, since it uses less digits than its factorization.

669608649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2400068 (or 2400065 counting only the distinct ones).

The product of its (nonzero) digits is 3359232, while the sum is 54.

The square root of 669608649 is about 25876.7975027823. The cubic root of 669608649 is about 874.8636082375.

The spelling of 669608649 in words is "six hundred sixty-nine million, six hundred eight thousand, six hundred forty-nine".