660987 has 8 divisors (see below), whose sum is σ = 979280. Its totient is φ = 440640.

The previous prime is 660983. The next prime is 661009. The reversal of 660987 is 789066.

It is not a de Polignac number, because 660987 - 2² = 660983 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12214 + ... + 12267.

It is an arithmetic number, because the mean of its divisors is an integer number (122410).

2⁶⁶⁰⁹⁸⁷ is an apocalyptic number.

660987 is a deficient number, since it is larger than the sum of its proper divisors (318293).

660987 is a wasteful number, since it uses less digits than its factorization.

660987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24490 (or 24484 counting only the distinct ones).

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

The square root of 660987 is about 813.0110700353. The cubic root of 660987 is about 87.1092563154.

The spelling of 660987 in words is "six hundred sixty thousand, nine hundred eighty-seven".