18518549 has 4 divisors (see below), whose sum is σ = 21164064. Its totient is φ = 15873036.

The previous prime is 18518531. The next prime is 18518551. The reversal of 18518549 is 94581581.

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 a de Polignac number, because none of the positive numbers 2^k-18518549 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 (18518569) 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, 1322747 + ... + 1322760.

It is an arithmetic number, because the mean of its divisors is an integer number (5291016).

Almost surely, 2^18518549 is an apocalyptic number.

It is an amenable number.

18518549 is a deficient number, since it is larger than the sum of its proper divisors (2645515).

18518549 is an equidigital number, since it uses as much as digits as its factorization.

18518549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2645514.

The product of its digits is 57600, while the sum is 41.

The square root of 18518549 is about 4303.3183707460. The cubic root of 18518549 is about 264.5669871536.

The spelling of 18518549 in words is "eighteen million, five hundred eighteen thousand, five hundred forty-nine".