18458213 has 4 divisors (see below), whose sum is σ = 19260768. Its totient is φ = 17655660.

The previous prime is 18458203. The next prime is 18458233. The reversal of 18458213 is 31285481.

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, and also an emirpimes, since its reverse is a distinct semiprime: 31285481 = 853 ⋅36677.

It is a cyclic number.

It is not a de Polignac number, because 18458213 - 2⁴ = 18458197 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18458213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18458203) 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, 401243 + ... + 401288.

It is an arithmetic number, because the mean of its divisors is an integer number (4815192).

Almost surely, 2^18458213 is an apocalyptic number.

It is an amenable number.

18458213 is a deficient number, since it is larger than the sum of its proper divisors (802555).

18458213 is an equidigital number, since it uses as much as digits as its factorization.

18458213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 802554.

The product of its digits is 7680, while the sum is 32.

The square root of 18458213 is about 4296.3022472820. The cubic root of 18458213 is about 264.2793425574.

The spelling of 18458213 in words is "eighteen million, four hundred fifty-eight thousand, two hundred thirteen".