664345920 has 336 divisors, whose sum is σ = 2543495040. Its totient is φ = 146313216.

The previous prime is 664345901. The next prime is 664345939. The reversal of 664345920 is 29543466.

It is an interprime number because it is at equal distance from previous prime (664345901) and next prime (664345939).

It is a tau number, because it is divible by the number of its divisors (336).

It is a congruent 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 47 ways as a sum of consecutive naturals, for example, 1363917 + ... + 1364403.

Almost surely, 2^664345920 is an apocalyptic number.

664345920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664345920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1271747520).

664345920 is an abundant number, since it is smaller than the sum of its proper divisors (1879149120).

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

664345920 is a wasteful number, since it uses less digits than its factorization.

664345920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550 (or 533 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 39.

The square root of 664345920 is about 25774.9087292273. The cubic root of 664345920 is about 872.5656067338.

The spelling of 664345920 in words is "six hundred sixty-four million, three hundred forty-five thousand, nine hundred twenty".