18555481 has 4 divisors (see below), whose sum is σ = 21206272. Its totient is φ = 15904692.

The previous prime is 18555469. The next prime is 18555487. The reversal of 18555481 is 18455581.

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 18555481 - 2²³ = 10166873 is a prime.

It is a super-2 number, since 2×18555481² = 688611750282722, 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 18555481.

It is not an unprimeable number, because it can be changed into a prime (18555487) 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, 1325385 + ... + 1325398.

It is an arithmetic number, because the mean of its divisors is an integer number (5301568).

Almost surely, 2^18555481 is an apocalyptic number.

It is an amenable number.

18555481 is a deficient number, since it is larger than the sum of its proper divisors (2650791).

18555481 is an equidigital number, since it uses as much as digits as its factorization.

18555481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2650790.

The product of its digits is 32000, while the sum is 37.

The square root of 18555481 is about 4307.6073405082. The cubic root of 18555481 is about 264.7427478580.

The spelling of 18555481 in words is "eighteen million, five hundred fifty-five thousand, four hundred eighty-one".