664717872 has 160 divisors (see below), whose sum is σ = 2182082560. Its totient is φ = 169620480.

The previous prime is 664717849. The next prime is 664717897. The reversal of 664717872 is 278717466.

664717872 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

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

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 132954 + ... + 137862.

It is an arithmetic number, because the mean of its divisors is an integer number (13638016).

Almost surely, 2^664717872 is an apocalyptic number.

664717872 is a gapful number since it is divisible by the number (62) 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 664717872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1091041280).

664717872 is an abundant number, since it is smaller than the sum of its proper divisors (1517364688).

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

664717872 is a wasteful number, since it uses less digits than its factorization.

664717872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4971 (or 4965 counting only the distinct ones).

The product of its digits is 790272, while the sum is 48.

The square root of 664717872 is about 25782.1231088520. The cubic root of 664717872 is about 872.7284194903.

The spelling of 664717872 in words is "six hundred sixty-four million, seven hundred seventeen thousand, eight hundred seventy-two".