18391004 has 6 divisors (see below), whose sum is σ = 32184264. Its totient is φ = 9195500.

The previous prime is 18390979. The next prime is 18391013. The reversal of 18391004 is 40019381.

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, 2298872 + ... + 2298879.

It is an arithmetic number, because the mean of its divisors is an integer number (5364044).

Almost surely, 2^18391004 is an apocalyptic number.

It is an amenable number.

18391004 is a deficient number, since it is larger than the sum of its proper divisors (13793260).

18391004 is a wasteful number, since it uses less digits than its factorization.

18391004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4597755 (or 4597753 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 18391004 is about 4288.4733880485. The cubic root of 18391004 is about 263.9581927982.

The spelling of 18391004 in words is "eighteen million, three hundred ninety-one thousand, four".