18293993 has 8 divisors (see below), whose sum is σ = 19134528. Its totient is φ = 17457264.

The previous prime is 18293987. The next prime is 18294013. The reversal of 18293993 is 39939281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18293993 - 2²² = 14099689 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18293393) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14171 + ... + 15407.

It is an arithmetic number, because the mean of its divisors is an integer number (2391816).

Almost surely, 2^18293993 is an apocalyptic number.

It is an amenable number.

18293993 is a deficient number, since it is larger than the sum of its proper divisors (840535).

18293993 is a wasteful number, since it uses less digits than its factorization.

18293993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1903.

The product of its digits is 104976, while the sum is 44.

The square root of 18293993 is about 4277.1477645740. The cubic root of 18293993 is about 263.4932552430.

The spelling of 18293993 in words is "eighteen million, two hundred ninety-three thousand, nine hundred ninety-three".