669926408 has 12 divisors (see below), whose sum is σ = 1256249295. Its totient is φ = 334926600.

The previous prime is 669926381. The next prime is 669926417. The reversal of 669926408 is 804629966.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in only one way, i.e., 334963204 + 334963204 = 18302^2 + 18302^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=18302.

It is a Duffinian 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 in 2 ways as a sum of consecutive naturals, for example, 68633 + ... + 77783.

Almost surely, 2^669926408 is an apocalyptic number.

It is an amenable number.

669926408 is a deficient number, since it is larger than the sum of its proper divisors (586322887).

669926408 is an frugal number, since it uses more digits than its factorization.

669926408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18308 (or 9153 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 50.

The square root of 669926408 is about 25882.9366185524. The cubic root of 669926408 is about 875.0019735466.

Multiplying 669926408 by its sum of digits (50), we get a square (33496320400 = 183020²).

The spelling of 669926408 in words is "six hundred sixty-nine million, nine hundred twenty-six thousand, four hundred eight".