660768820 has 24 divisors (see below), whose sum is σ = 1391410944. Its totient is φ = 263584416.

The previous prime is 660768811. The next prime is 660768853. The reversal of 660768820 is 28867066.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37672 + ... + 52351.

It is an arithmetic number, because the mean of its divisors is an integer number (57975456).

Almost surely, 2^660768820 is an apocalyptic number.

It is an amenable number.

660768820 is an abundant number, since it is smaller than the sum of its proper divisors (730642124).

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

660768820 is a wasteful number, since it uses less digits than its factorization.

660768820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90399 (or 90397 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 43.

The square root of 660768820 is about 25705.4239412619. The cubic root of 660768820 is about 870.9967085757.

The spelling of 660768820 in words is "six hundred sixty million, seven hundred sixty-eight thousand, eight hundred twenty".