660990680 has 128 divisors (see below), whose sum is σ = 1767260160. Its totient is φ = 217728000.

The previous prime is 660990667. The next prime is 660990727. The reversal of 660990680 is 86099066.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 2352140 + ... + 2352420.

It is an arithmetic number, because the mean of its divisors is an integer number (13806720).

Almost surely, 2^660990680 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 660990680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (883630080).

660990680 is an abundant number, since it is smaller than the sum of its proper divisors (1106269480).

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

660990680 is a wasteful number, since it uses less digits than its factorization.

660990680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 601 (or 597 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 660990680 is about 25709.7390107329. The cubic root of 660990680 is about 871.0941797338.

The spelling of 660990680 in words is "six hundred sixty million, nine hundred ninety thousand, six hundred eighty".