18640243 has 8 divisors (see below), whose sum is σ = 19335600. Its totient is φ = 17948448.

The previous prime is 18640241. The next prime is 18640253. The reversal of 18640243 is 34204681.

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

It is not a de Polignac number, because 18640243 - 2¹ = 18640241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18640241) 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, 14553 + ... + 15781.

It is an arithmetic number, because the mean of its divisors is an integer number (2416950).

Almost surely, 2^18640243 is an apocalyptic number.

18640243 is a deficient number, since it is larger than the sum of its proper divisors (695357).

18640243 is a wasteful number, since it uses less digits than its factorization.

18640243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1781.

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 18640243 is about 4317.4347707869. The cubic root of 18640243 is about 265.1452532271.

The spelling of 18640243 in words is "eighteen million, six hundred forty thousand, two hundred forty-three".