18908549 has 6 divisors (see below), whose sum is σ = 20783910. Its totient is φ = 17189480.

The previous prime is 18908537. The next prime is 18908563. The reversal of 18908549 is 94580981.

It can be written as a sum of positive squares in only one way, i.e., 13823524 + 5085025 = 3718^2 + 2255^2 .

It is not a de Polignac number, because 18908549 - 2⁸ = 18908293 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 (18908509) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 78014 + ... + 78255.

It is an arithmetic number, because the mean of its divisors is an integer number (3463985).

Almost surely, 2^18908549 is an apocalyptic number.

It is an amenable number.

18908549 is a deficient number, since it is larger than the sum of its proper divisors (1875361).

18908549 is a wasteful number, since it uses less digits than its factorization.

18908549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156291 (or 156280 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 44.

The square root of 18908549 is about 4348.3961411077. The cubic root of 18908549 is about 266.4113568567.

The spelling of 18908549 in words is "eighteen million, nine hundred eight thousand, five hundred forty-nine".