18231493 has 4 divisors (see below), whose sum is σ = 20836000. Its totient is φ = 15626988.

The previous prime is 18231481. The next prime is 18231509. The reversal of 18231493 is 39413281.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18231493 - 2⁵ = 18231461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18231403) 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, 1302243 + ... + 1302256.

It is an arithmetic number, because the mean of its divisors is an integer number (5209000).

Almost surely, 2^18231493 is an apocalyptic number.

It is an amenable number.

18231493 is a deficient number, since it is larger than the sum of its proper divisors (2604507).

18231493 is an equidigital number, since it uses as much as digits as its factorization.

18231493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2604506.

The product of its digits is 5184, while the sum is 31.

The square root of 18231493 is about 4269.8352427231. The cubic root of 18231493 is about 263.1928448226.

The spelling of 18231493 in words is "eighteen million, two hundred thirty-one thousand, four hundred ninety-three".