18057581 has 6 divisors (see below), whose sum is σ = 19058382. Its totient is φ = 17106840.

The previous prime is 18057551. The next prime is 18057631. The reversal of 18057581 is 18575081.

It can be written as a sum of positive squares in only one way, i.e., 16532356 + 1525225 = 4066^2 + 1235^2 .

It is not a de Polignac number, because 18057581 - 2²² = 13863277 is a prime.

It is a super-2 number, since 2×18057581² = 652152463143122, 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 (18057511) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 24650 + ... + 25371.

It is an arithmetic number, because the mean of its divisors is an integer number (3176397).

Almost surely, 2^18057581 is an apocalyptic number.

It is an amenable number.

18057581 is a deficient number, since it is larger than the sum of its proper divisors (1000801).

18057581 is an equidigital number, since it uses as much as digits as its factorization.

18057581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50059 (or 50040 counting only the distinct ones).

The product of its (nonzero) digits is 11200, while the sum is 35.

The square root of 18057581 is about 4249.4212547122. The cubic root of 18057581 is about 262.3532955013.

The spelling of 18057581 in words is "eighteen million, fifty-seven thousand, five hundred eighty-one".