669121920 has 96 divisors (see below), whose sum is σ = 2310581520. Its totient is φ = 178430976.

The previous prime is 669121913. The next prime is 669121933. The reversal of 669121920 is 29121966.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 52324 + ... + 63843.

Almost surely, 2^669121920 is an apocalyptic number.

669121920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

669121920 is an abundant number, since it is smaller than the sum of its proper divisors (1641459600).

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

669121920 is a wasteful number, since it uses less digits than its factorization.

669121920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116192 (or 116177 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 669121920 is about 25867.3910551490. The cubic root of 669121920 is about 874.6515815529.

The spelling of 669121920 in words is "six hundred sixty-nine million, one hundred twenty-one thousand, nine hundred twenty".