669805920 has 144 divisors (see below), whose sum is σ = 2612282400. Its totient is φ = 153096192.

The previous prime is 669805897. The next prime is 669805943. The reversal of 669805920 is 29508966.

It is an interprime number because it is at equal distance from previous prime (669805897) and next prime (669805943).

It is a tau number, because it is divible by the number of its divisors (144).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23145 + ... + 43304.

It is an arithmetic number, because the mean of its divisors is an integer number (18140850).

Almost surely, 2^669805920 is an apocalyptic number.

669805920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

669805920 is an abundant number, since it is smaller than the sum of its proper divisors (1942476480).

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

669805920 is a wasteful number, since it uses less digits than its factorization.

669805920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66477 (or 66466 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The square root of 669805920 is about 25880.6089572869. The cubic root of 669805920 is about 874.9495132775.

It can be divided in two parts, 66980 and 5920, that added together give a square (72900 = 270²).

The spelling of 669805920 in words is "six hundred sixty-nine million, eight hundred five thousand, nine hundred twenty".