18449999 has 4 divisors (see below), whose sum is σ = 18752520. Its totient is φ = 18147480.

The previous prime is 18449983. The next prime is 18450001. The reversal of 18449999 is 99994481.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18449999 - 2⁴ = 18449983 is a prime.

It is a Duffinian number.

18449999 is a modest number, since divided by 9999 gives 1844 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 18449999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18449099) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 151169 + ... + 151290.

It is an arithmetic number, because the mean of its divisors is an integer number (4688130).

Almost surely, 2^18449999 is an apocalyptic number.

18449999 is a deficient number, since it is larger than the sum of its proper divisors (302521).

18449999 is an equidigital number, since it uses as much as digits as its factorization.

18449999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302520.

The product of its digits is 839808, while the sum is 53.

The square root of 18449999 is about 4295.3462025779. The cubic root of 18449999 is about 264.2401348507.

The spelling of 18449999 in words is "eighteen million, four hundred forty-nine thousand, nine hundred ninety-nine".