664075680 has 192 divisors, whose sum is σ = 2155507200. Its totient is φ = 171791360.

The previous prime is 664075663. The next prime is 664075681. The reversal of 664075680 is 86570466.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (664075681) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3709831 + ... + 3710009.

It is an arithmetic number, because the mean of its divisors is an integer number (11226600).

Almost surely, 2^664075680 is an apocalyptic number.

664075680 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 664075680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1077753600).

664075680 is an abundant number, since it is smaller than the sum of its proper divisors (1491431520).

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

664075680 is a wasteful number, since it uses less digits than its factorization.

664075680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 387 (or 379 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 42.

The square root of 664075680 is about 25769.6658884045. The cubic root of 664075680 is about 872.4472777616.

The spelling of 664075680 in words is "six hundred sixty-four million, seventy-five thousand, six hundred eighty".