664980840 has 160 divisors (see below), whose sum is σ = 2366745480. Its totient is φ = 166883328.

The previous prime is 664980839. The next prime is 664980889. The reversal of 664980840 is 48089466.

It is a happy number.

664980840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 429235524 + 235745316 = 20718^2 + 15354^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 49044 + ... + 61116.

Almost surely, 2^664980840 is an apocalyptic number.

664980840 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 664980840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1183372740).

664980840 is an abundant number, since it is smaller than the sum of its proper divisors (1701764640).

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

664980840 is a wasteful number, since it uses less digits than its factorization.

664980840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12113 (or 12100 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The square root of 664980840 is about 25787.2224173136. Note that the first 3 decimals coincide. The cubic root of 664980840 is about 872.8434905599.

The spelling of 664980840 in words is "six hundred sixty-four million, nine hundred eighty thousand, eight hundred forty".