18275581 has 4 divisors (see below), whose sum is σ = 18407200. Its totient is φ = 18143964.

The previous prime is 18275573. The next prime is 18275633. The reversal of 18275581 is 18557281.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18557281 = 19 ⋅976699.

It is a cyclic number.

It is not a de Polignac number, because 18275581 - 2³ = 18275573 is a prime.

It is a super-2 number, since 2×18275581² = 667993721775122, 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 18275581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18275531) 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, 65601 + ... + 65878.

It is an arithmetic number, because the mean of its divisors is an integer number (4601800).

Almost surely, 2^18275581 is an apocalyptic number.

It is an amenable number.

18275581 is a deficient number, since it is larger than the sum of its proper divisors (131619).

18275581 is a wasteful number, since it uses less digits than its factorization.

18275581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131618.

The product of its digits is 22400, while the sum is 37.

The square root of 18275581 is about 4274.9948537981. The cubic root of 18275581 is about 263.4048279233.

The spelling of 18275581 in words is "eighteen million, two hundred seventy-five thousand, five hundred eighty-one".