18481381 has 8 divisors (see below), whose sum is σ = 19202400. Its totient is φ = 17766000.

The previous prime is 18481369. The next prime is 18481391. The reversal of 18481381 is 18318481.

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 18481381 - 2²³ = 10092773 is a prime.

It is a super-2 number, since 2×18481381² = 683122887334322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18481321) 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, 6010 + ... + 8548.

It is an arithmetic number, because the mean of its divisors is an integer number (2400300).

Almost surely, 2^18481381 is an apocalyptic number.

It is an amenable number.

18481381 is a deficient number, since it is larger than the sum of its proper divisors (721019).

18481381 is a wasteful number, since it uses less digits than its factorization.

18481381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2819.

The product of its digits is 6144, while the sum is 34.

The square root of 18481381 is about 4298.9976738770. The cubic root of 18481381 is about 264.3898672308.

The spelling of 18481381 in words is "eighteen million, four hundred eighty-one thousand, three hundred eighty-one".