660500640 has 144 divisors (see below), whose sum is σ = 2306592288. Its totient is φ = 172021248.

The previous prime is 660500623. The next prime is 660500669. The reversal of 660500640 is 46005066.

660500640 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×660500640² = 872522190880819200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 56587 + ... + 67253.

It is an arithmetic number, because the mean of its divisors is an integer number (16018002).

Almost surely, 2^660500640 is an apocalyptic number.

660500640 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 660500640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1153296144).

660500640 is an abundant number, since it is smaller than the sum of its proper divisors (1646091648).

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

660500640 is a wasteful number, since it uses less digits than its factorization.

660500640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10731 (or 10720 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 660500640 is about 25700.2070030574. The cubic root of 660500640 is about 870.8788582281.

The spelling of 660500640 in words is "six hundred sixty million, five hundred thousand, six hundred forty".