664791624 has 192 divisors, whose sum is σ = 2179632000. Its totient is φ = 189749952.

The previous prime is 664791623. The next prime is 664791629. The reversal of 664791624 is 426197466.

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

It is a nialpdrome in base 14.

It is a self number, because there is not a number n which added to its sum of digits gives 664791624.

It is not an unprimeable number, because it can be changed into a prime (664791623) 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 47 ways as a sum of consecutive naturals, for example, 666294 + ... + 667290.

It is an arithmetic number, because the mean of its divisors is an integer number (11352250).

Almost surely, 2^664791624 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 664791624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1089816000).

664791624 is an abundant number, since it is smaller than the sum of its proper divisors (1514840376).

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

664791624 is an equidigital number, since it uses as much as digits as its factorization.

664791624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1039 (or 1009 counting only the distinct ones).

The product of its digits is 435456, while the sum is 45.

The square root of 664791624 is about 25783.5533625604. The cubic root of 664791624 is about 872.7606953819.

The spelling of 664791624 in words is "six hundred sixty-four million, seven hundred ninety-one thousand, six hundred twenty-four".