664694480 has 80 divisors (see below), whose sum is σ = 1697569920. Its totient is φ = 240920064.

The previous prime is 664694479. The next prime is 664694519. The reversal of 664694480 is 84496466.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 25454 + ... + 44466.

It is an arithmetic number, because the mean of its divisors is an integer number (21219624).

Almost surely, 2^664694480 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664694480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (848784960).

664694480 is an abundant number, since it is smaller than the sum of its proper divisors (1032875440).

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

664694480 is a wasteful number, since it uses less digits than its factorization.

664694480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19068 (or 19062 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 47.

The square root of 664694480 is about 25781.6694571938. The cubic root of 664694480 is about 872.7181820128.

The spelling of 664694480 in words is "six hundred sixty-four million, six hundred ninety-four thousand, four hundred eighty".