666626 has 8 divisors (see below), whose sum is σ = 1007100. Its totient is φ = 330928.

The previous prime is 666607. The next prime is 666637. The reversal of 666626 is 626666.

It can be written as a sum of positive squares in 2 ways, for example, as 664225 + 2401 = 815^2 + 49^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 666592 and 666601.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 821 + ... + 1416.

2⁶⁶⁶⁶²⁶ is an apocalyptic number.

666626 is a deficient number, since it is larger than the sum of its proper divisors (340474).

666626 is a wasteful number, since it uses less digits than its factorization.

666626 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2388.

The product of its digits is 15552, while the sum is 32.

The square root of 666626 is about 816.4716774022. The cubic root of 666626 is about 87.3562701572.

The spelling of 666626 in words is "six hundred sixty-six thousand, six hundred twenty-six".