666896 has 10 divisors (see below), whose sum is σ = 1292142. Its totient is φ = 333440.

The previous prime is 666889. The next prime is 666901. The reversal of 666896 is 698666.

It can be written as a sum of positive squares in only one way, i.e., 640000 + 26896 = 800^2 + 164^2 .

It is an unprimeable number.

666896 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20825 + ... + 20856.

2⁶⁶⁶⁸⁹⁶ is an apocalyptic number.

It is an amenable number.

666896 is a deficient number, since it is larger than the sum of its proper divisors (625246).

666896 is a wasteful number, since it uses less digits than its factorization.

666896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41689 (or 41683 counting only the distinct ones).

The product of its digits is 93312, while the sum is 41.

The square root of 666896 is about 816.6370062641. The cubic root of 666896 is about 87.3680623812.

The spelling of 666896 in words is "six hundred sixty-six thousand, eight hundred ninety-six".