664390632 has 64 divisors (see below), whose sum is σ = 1770624000. Its totient is φ = 207140544.

The previous prime is 664390631. The next prime is 664390633. The reversal of 664390632 is 236093466.

It is an interprime number because it is at equal distance from previous prime (664390631) and next prime (664390633).

It is not an unprimeable number, because it can be changed into a prime (664390631) by changing a digit.

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, 26803 + ... + 45245.

It is an arithmetic number, because the mean of its divisors is an integer number (27666000).

Almost surely, 2^664390632 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 664390632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (885312000).

664390632 is an abundant number, since it is smaller than the sum of its proper divisors (1106233368).

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

664390632 is a wasteful number, since it uses less digits than its factorization.

664390632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18550 (or 18546 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 39.

The square root of 664390632 is about 25775.7760697908. The cubic root of 664390632 is about 872.5851815150.

The spelling of 664390632 in words is "six hundred sixty-four million, three hundred ninety thousand, six hundred thirty-two".