664721934240 has 1152 divisors, whose sum is σ = 2850994298880. Its totient is φ = 128546611200.

The previous prime is 664721934169. The next prime is 664721934263. The reversal of 664721934240 is 42439127466.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 664721934240.

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 191 ways as a sum of consecutive naturals, for example, 180090795 + ... + 180094485.

It is an arithmetic number, because the mean of its divisors is an integer number (2474821440).

Almost surely, 2^664721934240 is an apocalyptic number.

664721934240 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 664721934240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1425497149440).

664721934240 is an abundant number, since it is smaller than the sum of its proper divisors (2186272364640).

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

664721934240 is a wasteful number, since it uses less digits than its factorization.

664721934240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3786 (or 3771 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 48.

The spelling of 664721934240 in words is "six hundred sixty-four billion, seven hundred twenty-one million, nine hundred thirty-four thousand, two hundred forty".