18044557 has 2 divisors, whose sum is σ = 18044558. Its totient is φ = 18044556.

The previous prime is 18044549. The next prime is 18044561. The reversal of 18044557 is 75544081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16232841 + 1811716 = 4029^2 + 1346^2 .

It is an emirp because it is prime and its reverse (75544081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18044557 - 2³ = 18044549 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18044597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9022278 + 9022279.

It is an arithmetic number, because the mean of its divisors is an integer number (9022279).

Almost surely, 2^18044557 is an apocalyptic number.

It is an amenable number.

18044557 is a deficient number, since it is larger than the sum of its proper divisors (1).

18044557 is an equidigital number, since it uses as much as digits as its factorization.

18044557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22400, while the sum is 34.

The square root of 18044557 is about 4247.8885343191. Note that the first 3 decimals coincide. The cubic root of 18044557 is about 262.2902063732.

The spelling of 18044557 in words is "eighteen million, forty-four thousand, five hundred fifty-seven".