990904 has 8 divisors (see below), whose sum is σ = 1857960. Its totient is φ = 495448.

The previous prime is 990893. The next prime is 990917. The reversal of 990904 is 409099.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

990904 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 as a sum of consecutive naturals, namely, 61924 + ... + 61939.

It is an arithmetic number, because the mean of its divisors is an integer number (232245).

2⁹⁹⁰⁹⁰⁴ is an apocalyptic number.

It is an amenable number.

990904 is a deficient number, since it is larger than the sum of its proper divisors (867056).

990904 is a wasteful number, since it uses less digits than its factorization.

990904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123869 (or 123865 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 990904 is about 995.4416105428. The cubic root of 990904 is about 99.6958760237.

The spelling of 990904 in words is "nine hundred ninety thousand, nine hundred four".