666650 has 24 divisors (see below), whose sum is σ = 1264800. Its totient is φ = 261360.

The previous prime is 666649. The next prime is 666667. The reversal of 666650 is 56666.

It is a super-4 number, since 4×666650⁴ (a number of 24 digits) contains 4444 as substring.

It is a nialpdrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3251 + ... + 3449.

It is an arithmetic number, because the mean of its divisors is an integer number (52700).

2⁶⁶⁶⁶⁵⁰ is an apocalyptic number.

666650 is a deficient number, since it is larger than the sum of its proper divisors (598150).

666650 is a wasteful number, since it uses less digits than its factorization.

666650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278 (or 273 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 666650 is about 816.4863746567. The cubic root of 666650 is about 87.3573184838.

The spelling of 666650 in words is "six hundred sixty-six thousand, six hundred fifty".