18197213 has 4 divisors (see below), whose sum is σ = 18620448. Its totient is φ = 17773980.

The previous prime is 18197203. The next prime is 18197219. The reversal of 18197213 is 31279181.

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.

It is a cyclic number.

It is not a de Polignac number, because 18197213 - 2⁶ = 18197149 is a prime.

It is a super-2 number, since 2×18197213² = 662277121934738, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 18197213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18197219) 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, 211553 + ... + 211638.

It is an arithmetic number, because the mean of its divisors is an integer number (4655112).

Almost surely, 2^18197213 is an apocalyptic number.

It is an amenable number.

18197213 is a deficient number, since it is larger than the sum of its proper divisors (423235).

18197213 is an equidigital number, since it uses as much as digits as its factorization.

18197213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423234.

The product of its digits is 3024, while the sum is 32.

The square root of 18197213 is about 4265.8191475964. The cubic root of 18197213 is about 263.0277840791.

The spelling of 18197213 in words is "eighteen million, one hundred ninety-seven thousand, two hundred thirteen".