660690 has 32 divisors (see below), whose sum is σ = 1762560. Its totient is φ = 176112.

The previous prime is 660683. The next prime is 660719. The reversal of 660690 is 96066.

It is a super-2 number, since 2×660690² = 873022552200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

660690 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 954 + ... + 1493.

It is an arithmetic number, because the mean of its divisors is an integer number (55080).

2⁶⁶⁰⁶⁹⁰ is an apocalyptic number.

660690 is an abundant number, since it is smaller than the sum of its proper divisors (1101870).

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

660690 is a wasteful number, since it uses less digits than its factorization.

660690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2463 (or 2457 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 660690 is about 812.8283951733. The cubic root of 660690 is about 87.0962074834.

The spelling of 660690 in words is "six hundred sixty thousand, six hundred ninety".