18824213 has 4 divisors (see below), whose sum is σ = 18950700. Its totient is φ = 18697728.

The previous prime is 18824209. The next prime is 18824233. The reversal of 18824213 is 31242881.

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 9721924 + 9102289 = 3118^2 + 3017^2 .

It is a cyclic number.

It is not a de Polignac number, because 18824213 - 2² = 18824209 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18824203) 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, 63020 + ... + 63317.

It is an arithmetic number, because the mean of its divisors is an integer number (4737675).

Almost surely, 2^18824213 is an apocalyptic number.

It is an amenable number.

18824213 is a deficient number, since it is larger than the sum of its proper divisors (126487).

18824213 is a wasteful number, since it uses less digits than its factorization.

18824213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126486.

The product of its digits is 3072, while the sum is 29.

The square root of 18824213 is about 4338.6879353095. The cubic root of 18824213 is about 266.0146834565.

The spelling of 18824213 in words is "eighteen million, eight hundred twenty-four thousand, two hundred thirteen".