1998904 has 8 divisors (see below), whose sum is σ = 3747960. Its totient is φ = 999448.

The previous prime is 1998881. The next prime is 1998917. The reversal of 1998904 is 4098991.

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.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124924 + ... + 124939.

It is an arithmetic number, because the mean of its divisors is an integer number (468495).

2^1998904 is an apocalyptic number.

It is an amenable number.

1998904 is a deficient number, since it is larger than the sum of its proper divisors (1749056).

1998904 is a wasteful number, since it uses less digits than its factorization.

1998904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249869 (or 249865 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 1998904 is about 1413.8260147557. The cubic root of 1998904 is about 125.9690862264.

The spelling of 1998904 in words is "one million, nine hundred ninety-eight thousand, nine hundred four".