18213541 has 4 divisors (see below), whose sum is σ = 18237472. Its totient is φ = 18189612.

The previous prime is 18213499. The next prime is 18213551. The reversal of 18213541 is 14531281.

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 not a de Polignac number, because 18213541 - 2⁹ = 18213029 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 (18213551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10785 + ... + 12358.

It is an arithmetic number, because the mean of its divisors is an integer number (4559368).

Almost surely, 2^18213541 is an apocalyptic number.

It is an amenable number.

18213541 is a deficient number, since it is larger than the sum of its proper divisors (23931).

18213541 is an equidigital number, since it uses as much as digits as its factorization.

18213541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23930.

The product of its digits is 960, while the sum is 25.

The square root of 18213541 is about 4267.7325361367. The cubic root of 18213541 is about 263.1064304406.

The spelling of 18213541 in words is "eighteen million, two hundred thirteen thousand, five hundred forty-one".