18018149 has 4 divisors (see below), whose sum is σ = 18505164. Its totient is φ = 17531136.

The previous prime is 18018127. The next prime is 18018157. The reversal of 18018149 is 94181081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 94181081 = 19 ⋅4956899.

It can be written as a sum of positive squares in 2 ways, for example, as 9060100 + 8958049 = 3010^2 + 2993^2 .

It is a cyclic number.

It is not a de Polignac number, because 18018149 - 2²⁰ = 16969573 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18018349) 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, 243452 + ... + 243525.

It is an arithmetic number, because the mean of its divisors is an integer number (4626291).

Almost surely, 2^18018149 is an apocalyptic number.

It is an amenable number.

18018149 is a deficient number, since it is larger than the sum of its proper divisors (487015).

18018149 is an equidigital number, since it uses as much as digits as its factorization.

18018149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487014.

The product of its (nonzero) digits is 2304, while the sum is 32.

The square root of 18018149 is about 4244.7790284065. The cubic root of 18018149 is about 262.1621910110.

The spelling of 18018149 in words is "eighteen million, eighteen thousand, one hundred forty-nine".