666040 has 16 divisors (see below), whose sum is σ = 1498680. Its totient is φ = 266400.

The previous prime is 666031. The next prime is 666041. The reversal of 666040 is 40666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8286 + ... + 8365.

2⁶⁶⁶⁰⁴⁰ is an apocalyptic number.

It is an amenable number.

666040 is an abundant number, since it is smaller than the sum of its proper divisors (832640).

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

666040 is a wasteful number, since it uses less digits than its factorization.

666040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16662 (or 16658 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 666040 is about 816.1127373102. The cubic root of 666040 is about 87.3306657046.

The spelling of 666040 in words is "six hundred sixty-six thousand, forty".