18457381 has 4 divisors (see below), whose sum is σ = 18487264. Its totient is φ = 18427500.

The previous prime is 18457367. The next prime is 18457399. The reversal of 18457381 is 18375481.

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 18457381 - 2¹⁵ = 18424613 is a prime.

It is a super-2 number, since 2×18457381² = 681349826758322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18457381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18457321) 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 3 ways as a sum of consecutive naturals, for example, 13995 + ... + 15256.

It is an arithmetic number, because the mean of its divisors is an integer number (4621816).

Almost surely, 2^18457381 is an apocalyptic number.

It is an amenable number.

18457381 is a deficient number, since it is larger than the sum of its proper divisors (29883).

18457381 is an equidigital number, since it uses as much as digits as its factorization.

18457381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29882.

The product of its digits is 26880, while the sum is 37.

The square root of 18457381 is about 4296.2054187387. The cubic root of 18457381 is about 264.2753717195.

The spelling of 18457381 in words is "eighteen million, four hundred fifty-seven thousand, three hundred eighty-one".