669969966 has 32 divisors (see below), whose sum is σ = 1432829088. Its totient is φ = 208102400.

The previous prime is 669969947. The next prime is 669969973.

669969966 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 669969897 and 669969906.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22215 + ... + 42818.

It is an arithmetic number, because the mean of its divisors is an integer number (44775909).

Almost surely, 2^669969966 is an apocalyptic number.

669969966 is an abundant number, since it is smaller than the sum of its proper divisors (762859122).

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

669969966 is a wasteful number, since it uses less digits than its factorization.

669969966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65156.

The product of its digits is 51018336, while the sum is 66.

The square root of 669969966 is about 25883.7780472635. The cubic root of 669969966 is about 875.0209370772.

The spelling of 669969966 in words is "six hundred sixty-nine million, nine hundred sixty-nine thousand, nine hundred sixty-six".