18181849 has 4 divisors (see below), whose sum is σ = 20779264. Its totient is φ = 15584436.

The previous prime is 18181831. The next prime is 18181861. The reversal of 18181849 is 94818181.

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 not a de Polignac number, because 18181849 - 2⁵ = 18181817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18181829) 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, 1298697 + ... + 1298710.

It is an arithmetic number, because the mean of its divisors is an integer number (5194816).

Almost surely, 2^18181849 is an apocalyptic number.

It is an amenable number.

18181849 is a deficient number, since it is larger than the sum of its proper divisors (2597415).

18181849 is an equidigital number, since it uses as much as digits as its factorization.

18181849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2597414.

The product of its digits is 18432, while the sum is 40.

The square root of 18181849 is about 4264.0179408628. The cubic root of 18181849 is about 262.9537380016.

Adding to 18181849 its product of digits (18432), we get a palindrome (18200281).

The spelling of 18181849 in words is "eighteen million, one hundred eighty-one thousand, eight hundred forty-nine".