18993105 has 12 divisors (see below), whose sum is σ = 32921460. Its totient is φ = 10129632.

The previous prime is 18993089. The next prime is 18993113. The reversal of 18993105 is 50139981.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 2663424 + 16329681 = 1632^2 + 4041^2 .

It is not a de Polignac number, because 18993105 - 2⁴ = 18993089 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18993105.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 210990 + ... + 211079.

It is an arithmetic number, because the mean of its divisors is an integer number (2743455).

Almost surely, 2^18993105 is an apocalyptic number.

18993105 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18993105 is a deficient number, since it is larger than the sum of its proper divisors (13928355).

18993105 is a wasteful number, since it uses less digits than its factorization.

18993105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 422080 (or 422077 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 36.

The square root of 18993105 is about 4358.1079610308. The cubic root of 18993105 is about 266.8078826697.

The spelling of 18993105 in words is "eighteen million, nine hundred ninety-three thousand, one hundred five".