18404889 has 4 divisors (see below), whose sum is σ = 24539856. Its totient is φ = 12269924.

The previous prime is 18404887. The next prime is 18404891. The reversal of 18404889 is 98840481.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98840481 = 3 ⋅32946827.

It is an interprime number because it is at equal distance from previous prime (18404887) and next prime (18404891).

It is a cyclic number.

It is not a de Polignac number, because 18404889 - 2¹ = 18404887 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18404889.

It is not an unprimeable number, because it can be changed into a prime (18404887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3067479 + ... + 3067484.

It is an arithmetic number, because the mean of its divisors is an integer number (6134964).

Almost surely, 2^18404889 is an apocalyptic number.

It is an amenable number.

18404889 is a deficient number, since it is larger than the sum of its proper divisors (6134967).

18404889 is an equidigital number, since it uses as much as digits as its factorization.

18404889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6134966.

The product of its (nonzero) digits is 73728, while the sum is 42.

The square root of 18404889 is about 4290.0919570564. The cubic root of 18404889 is about 264.0246045709.

The spelling of 18404889 in words is "eighteen million, four hundred four thousand, eight hundred eighty-nine".