18949393 has 4 divisors (see below), whose sum is σ = 19003428. Its totient is φ = 18895360.

The previous prime is 18949391. The next prime is 18949417. The reversal of 18949393 is 39394981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 39394981 = 163 ⋅241687.

It can be written as a sum of positive squares in 2 ways, for example, as 7579009 + 11370384 = 2753^2 + 3372^2 .

It is a cyclic number.

It is not a de Polignac number, because 18949393 - 2¹ = 18949391 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18949391) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26488 + ... + 27193.

It is an arithmetic number, because the mean of its divisors is an integer number (4750857).

Almost surely, 2^18949393 is an apocalyptic number.

It is an amenable number.

18949393 is a deficient number, since it is larger than the sum of its proper divisors (54035).

18949393 is an equidigital number, since it uses as much as digits as its factorization.

18949393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54034.

The product of its digits is 209952, while the sum is 46.

The square root of 18949393 is about 4353.0900519057. The cubic root of 18949393 is about 266.6030422863.

The spelling of 18949393 in words is "eighteen million, nine hundred forty-nine thousand, three hundred ninety-three".