990666 has 24 divisors (see below), whose sum is σ = 2193984. Its totient is φ = 322920.

The previous prime is 990643. The next prime is 990673. The reversal of 990666 is 666099.

It is a self number, because there is not a number n which added to its sum of digits gives 990666.

It is an unprimeable number.

990666 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 261 + ... + 1431.

It is an arithmetic number, because the mean of its divisors is an integer number (91416).

2⁹⁹⁰⁶⁶⁶ is an apocalyptic number.

990666 is an abundant number, since it is smaller than the sum of its proper divisors (1203318).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

990666 is a wasteful number, since it uses less digits than its factorization.

990666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1226 (or 1223 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 990666 is about 995.3220584313. The cubic root of 990666 is about 99.6878935759.

It can be divided in two parts, 9906 and 66, that multiplied together give a triangular number (653796 = T₁₁₄₃).

The spelling of 990666 in words is "nine hundred ninety thousand, six hundred sixty-six".