666239 has 4 divisors (see below), whose sum is σ = 761424. Its totient is φ = 571056.

The previous prime is 666233. The next prime is 666269. The reversal of 666239 is 932666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 666239 - 2⁸ = 665983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666233) 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, 47582 + ... + 47595.

It is an arithmetic number, because the mean of its divisors is an integer number (190356).

2⁶⁶⁶²³⁹ is an apocalyptic number.

666239 is a deficient number, since it is larger than the sum of its proper divisors (95185).

666239 is an equidigital number, since it uses as much as digits as its factorization.

666239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95184.

The product of its digits is 11664, while the sum is 32.

The square root of 666239 is about 816.2346476351. The cubic root of 666239 is about 87.3393624155.

The spelling of 666239 in words is "six hundred sixty-six thousand, two hundred thirty-nine".