664989696 has 208 divisors, whose sum is σ = 2254163200. Its totient is φ = 189775872.

The previous prime is 664989659. The next prime is 664989719. The reversal of 664989696 is 696989466.

It is a super-2 number, since 2×664989696² = 884422591572344832, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a nude number because it is divisible by every one of its digits.

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 15 ways as a sum of consecutive naturals, for example, 773715 + ... + 774573.

Almost surely, 2^664989696 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 664989696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1127081600).

664989696 is an abundant number, since it is smaller than the sum of its proper divisors (1589173504).

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

664989696 is an equidigital number, since it uses as much as digits as its factorization.

664989696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 899 (or 871 counting only the distinct ones).

The product of its digits is 30233088, while the sum is 63.

The square root of 664989696 is about 25787.3941296906. The cubic root of 664989696 is about 872.8473652920.

The spelling of 664989696 in words is "six hundred sixty-four million, nine hundred eighty-nine thousand, six hundred ninety-six".