669403890 has 24 divisors (see below), whose sum is σ = 1740450348. Its totient is φ = 178507680.

The previous prime is 669403879. The next prime is 669403957. The reversal of 669403890 is 98304966.

It can be written as a sum of positive squares in 2 ways, for example, as 650403009 + 19000881 = 25503^2 + 4359^2 .

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

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, 3718821 + ... + 3719000.

Almost surely, 2^669403890 is an apocalyptic number.

669403890 is an abundant number, since it is smaller than the sum of its proper divisors (1071046458).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

669403890 is a wasteful number, since it uses less digits than its factorization.

669403890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7437834 (or 7437831 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The square root of 669403890 is about 25872.8407794738. The cubic root of 669403890 is about 874.7744245726.

The spelling of 669403890 in words is "six hundred sixty-nine million, four hundred three thousand, eight hundred ninety".