18213386 has 4 divisors (see below), whose sum is σ = 27320082. Its totient is φ = 9106692.

The previous prime is 18213383. The next prime is 18213449. The reversal of 18213386 is 68331281.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 68331281 = 179 ⋅381739.

It can be written as a sum of positive squares in only one way, i.e., 11868025 + 6345361 = 3445^2 + 2519^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18213383) 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 as a sum of consecutive naturals, namely, 4553345 + ... + 4553348.

Almost surely, 2^18213386 is an apocalyptic number.

18213386 is a deficient number, since it is larger than the sum of its proper divisors (9106696).

18213386 is an equidigital number, since it uses as much as digits as its factorization.

18213386 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9106695.

The product of its digits is 6912, while the sum is 32.

The square root of 18213386 is about 4267.7143765721. The cubic root of 18213386 is about 263.1056840800.

The spelling of 18213386 in words is "eighteen million, two hundred thirteen thousand, three hundred eighty-six".