669403688 has 8 divisors (see below), whose sum is σ = 1255131930. Its totient is φ = 334701840.

The previous prime is 669403639. The next prime is 669403733. The reversal of 669403688 is 886304966.

It can be written as a sum of positive squares in only one way, i.e., 662444644 + 6959044 = 25738^2 + 2638^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41837723 + ... + 41837738.

Almost surely, 2^669403688 is an apocalyptic number.

It is an amenable number.

669403688 is a deficient number, since it is larger than the sum of its proper divisors (585728242).

669403688 is a wasteful number, since it uses less digits than its factorization.

669403688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83675467 (or 83675463 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 50.

The square root of 669403688 is about 25872.8368757661. The cubic root of 669403688 is about 874.7743365817.

The spelling of 669403688 in words is "six hundred sixty-nine million, four hundred three thousand, six hundred eighty-eight".