18549091 has 16 divisors (see below), whose sum is σ = 21562848. Its totient is φ = 15769600.

The previous prime is 18549071. The next prime is 18549101. The reversal of 18549091 is 19094581.

It is not a de Polignac number, because 18549091 - 2⁵ = 18549059 is a prime.

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 18549091.

It is not an unprimeable number, because it can be changed into a prime (18549071) 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 15 ways as a sum of consecutive naturals, for example, 52371 + ... + 52723.

It is an arithmetic number, because the mean of its divisors is an integer number (1347678).

Almost surely, 2^18549091 is an apocalyptic number.

18549091 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18549091 is a deficient number, since it is larger than the sum of its proper divisors (3013757).

18549091 is a wasteful number, since it uses less digits than its factorization.

18549091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 662.

The product of its (nonzero) digits is 12960, while the sum is 37.

The square root of 18549091 is about 4306.8655655825. The cubic root of 18549091 is about 264.7123543157.

Subtracting 18549091 from its reverse (19094581), we obtain a triangular number (545490 = T₁₀₄₄).

It can be divided in two parts, 185490 and 91, that added together give a palindrome (185581).

The spelling of 18549091 in words is "eighteen million, five hundred forty-nine thousand, ninety-one".