664782440 has 64 divisors (see below), whose sum is σ = 1725494400. Its totient is φ = 225785088.

The previous prime is 664782421. The next prime is 664782463. The reversal of 664782440 is 44287466.

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, 18866 + ... + 41054.

It is an arithmetic number, because the mean of its divisors is an integer number (26960850).

Almost surely, 2^664782440 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 664782440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (862747200).

664782440 is an abundant number, since it is smaller than the sum of its proper divisors (1060711960).

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

664782440 is a wasteful number, since it uses less digits than its factorization.

664782440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22314 (or 22310 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 41.

The square root of 664782440 is about 25783.3752639176. The cubic root of 664782440 is about 872.7566763426.

The spelling of 664782440 in words is "six hundred sixty-four million, seven hundred eighty-two thousand, four hundred forty".