18452381 has 12 divisors (see below), whose sum is σ = 19660212. Its totient is φ = 17305344.

The previous prime is 18452359. The next prime is 18452383. The reversal of 18452381 is 18325481.

It can be written as a sum of positive squares in 6 ways, for example, as 1716100 + 16736281 = 1310^2 + 4091^2 .

It is not a de Polignac number, because 18452381 - 2²² = 14258077 is a prime.

It is a super-2 number, since 2×18452381² = 680980729138322, 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 (18452383) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30821 + ... + 31413.

It is an arithmetic number, because the mean of its divisors is an integer number (1638351).

Almost surely, 2^18452381 is an apocalyptic number.

It is an amenable number.

18452381 is a deficient number, since it is larger than the sum of its proper divisors (1207831).

18452381 is an equidigital number, since it uses as much as digits as its factorization.

18452381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 688 (or 659 counting only the distinct ones).

The product of its digits is 7680, while the sum is 32.

The square root of 18452381 is about 4295.6234704639. The cubic root of 18452381 is about 264.2515059971.

The spelling of 18452381 in words is "eighteen million, four hundred fifty-two thousand, three hundred eighty-one".