666875 has 20 divisors (see below), whose sum is σ = 918456. Its totient is φ = 480000.

The previous prime is 666871. The next prime is 666889. The reversal of 666875 is 578666.

It is not a de Polignac number, because 666875 - 2² = 666871 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (666871) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6827 + ... + 6923.

2⁶⁶⁶⁸⁷⁵ is an apocalyptic number.

666875 is a deficient number, since it is larger than the sum of its proper divisors (251581).

666875 is an equidigital number, since it uses as much as digits as its factorization.

666875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128 (or 113 counting only the distinct ones).

The product of its digits is 60480, while the sum is 38.

The square root of 666875 is about 816.6241485531. The cubic root of 666875 is about 87.3671453224.

Subtracting from 666875 its reverse (578666), we obtain a square (88209 = 297²).

The spelling of 666875 in words is "six hundred sixty-six thousand, eight hundred seventy-five".