18464213 has 4 divisors (see below), whose sum is σ = 19100940. Its totient is φ = 17827488.

The previous prime is 18464203. The next prime is 18464231. The reversal of 18464213 is 31246481.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9690769 + 8773444 = 3113^2 + 2962^2 .

It is a cyclic number.

It is not a de Polignac number, because 18464213 - 2⁴ = 18464197 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 636697 = 18464213 / (1 + 8 + 4 + 6 + 4 + 2 + 1 + 3).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18464203) 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, 318320 + ... + 318377.

It is an arithmetic number, because the mean of its divisors is an integer number (4775235).

Almost surely, 2^18464213 is an apocalyptic number.

It is an amenable number.

18464213 is a deficient number, since it is larger than the sum of its proper divisors (636727).

18464213 is an equidigital number, since it uses as much as digits as its factorization.

18464213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 636726.

The product of its digits is 4608, while the sum is 29.

The square root of 18464213 is about 4297.0004654410. Note that the first 3 decimals coincide. The cubic root of 18464213 is about 264.3079748755.

The spelling of 18464213 in words is "eighteen million, four hundred sixty-four thousand, two hundred thirteen".