18939193 has 16 divisors (see below), whose sum is σ = 23637376. Its totient is φ = 14774400.

The previous prime is 18939163. The next prime is 18939197. The reversal of 18939193 is 39193981.

It is a cyclic number.

It is not a de Polignac number, because 18939193 - 2⁵ = 18939161 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18939197) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 5218 + ... + 8068.

It is an arithmetic number, because the mean of its divisors is an integer number (1477336).

Almost surely, 2^18939193 is an apocalyptic number.

18939193 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18939193 is a deficient number, since it is larger than the sum of its proper divisors (4698183).

18939193 is a wasteful number, since it uses less digits than its factorization.

18939193 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2944.

The product of its digits is 52488, while the sum is 43.

The square root of 18939193 is about 4351.9183126525. The cubic root of 18939193 is about 266.5551983773. Note that the first 3 decimals are identical.

The spelling of 18939193 in words is "eighteen million, nine hundred thirty-nine thousand, one hundred ninety-three".