18983993 has 16 divisors (see below), whose sum is σ = 23022336. Its totient is φ = 15301440.

The previous prime is 18983989. The next prime is 18983999. The reversal of 18983993 is 39938981.

It is not a de Polignac number, because 18983993 - 2² = 18983989 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18983999) 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 15 ways as a sum of consecutive naturals, for example, 8855 + ... + 10787.

It is an arithmetic number, because the mean of its divisors is an integer number (1438896).

Almost surely, 2^18983993 is an apocalyptic number.

It is an amenable number.

18983993 is a deficient number, since it is larger than the sum of its proper divisors (4038343).

18983993 is a wasteful number, since it uses less digits than its factorization.

18983993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2024.

The product of its digits is 419904, while the sum is 50.

The square root of 18983993 is about 4357.0624278291. The cubic root of 18983993 is about 266.7652085464.

The spelling of 18983993 in words is "eighteen million, nine hundred eighty-three thousand, nine hundred ninety-three".