669129808 has 10 divisors (see below), whose sum is σ = 1296439034. Its totient is φ = 334564896.

The previous prime is 669129781. The next prime is 669129817. The reversal of 669129808 is 808921966.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 341954064 + 327175744 = 18492^2 + 18088^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20910291 + ... + 20910322.

Almost surely, 2^669129808 is an apocalyptic number.

It is an amenable number.

669129808 is a deficient number, since it is larger than the sum of its proper divisors (627309226).

669129808 is a wasteful number, since it uses less digits than its factorization.

669129808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41820621 (or 41820615 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 49.

The square root of 669129808 is about 25867.5435246565. The cubic root of 669129808 is about 874.6550185073.

The spelling of 669129808 in words is "six hundred sixty-nine million, one hundred twenty-nine thousand, eight hundred eight".