660978 has 12 divisors (see below), whose sum is σ = 1432158. Its totient is φ = 220320.

The previous prime is 660973. The next prime is 660983. The reversal of 660978 is 879066.

660978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (660973) and next prime (660983).

It can be written as a sum of positive squares in only one way, i.e., 660969 + 9 = 813^2 + 3^2 .

It is not an unprimeable number, because it can be changed into a prime (660973) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18343 + ... + 18378.

2⁶⁶⁰⁹⁷⁸ is an apocalyptic number.

660978 is an abundant number, since it is smaller than the sum of its proper divisors (771180).

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

660978 is a wasteful number, since it uses less digits than its factorization.

660978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36729 (or 36726 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 660978 is about 813.0055350365. The cubic root of 660978 is about 87.1088609537.

The spelling of 660978 in words is "six hundred sixty thousand, nine hundred seventy-eight".