18213481 has 16 divisors (see below), whose sum is σ = 21728448. Its totient is φ = 15048000.

The previous prime is 18213463. The next prime is 18213497. The reversal of 18213481 is 18431281.

It is not a de Polignac number, because 18213481 - 2⁵ = 18213449 is a prime.

It is a super-2 number, since 2×18213481² = 663461780274722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18213781) 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 15 ways as a sum of consecutive naturals, for example, 8631 + ... + 10531.

It is an arithmetic number, because the mean of its divisors is an integer number (1358028).

Almost surely, 2^18213481 is an apocalyptic number.

18213481 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18213481 is a deficient number, since it is larger than the sum of its proper divisors (3514967).

18213481 is a wasteful number, since it uses less digits than its factorization.

18213481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1992.

The product of its digits is 1536, while the sum is 28.

The square root of 18213481 is about 4267.7255066370. The cubic root of 18213481 is about 263.1061415273.

It can be divided in two parts, 182 and 13481, that multiplied together give a palindrome (2453542).

The spelling of 18213481 in words is "eighteen million, two hundred thirteen thousand, four hundred eighty-one".