664016640 has 216 divisors, whose sum is σ = 2467639440. Its totient is φ = 151732224.

The previous prime is 664016623. The next prime is 664016663. The reversal of 664016640 is 46610466.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 186396 + ... + 189924.

Almost surely, 2^664016640 is an apocalyptic number.

664016640 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 664016640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1233819720).

664016640 is an abundant number, since it is smaller than the sum of its proper divisors (1803622800).

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

664016640 is a wasteful number, since it uses less digits than its factorization.

664016640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3567 (or 3546 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 664016640 is about 25768.5203300461. The cubic root of 664016640 is about 872.4214218662.

The spelling of 664016640 in words is "six hundred sixty-four million, sixteen thousand, six hundred forty".