18071213 has 4 divisors (see below), whose sum is σ = 18084288. Its totient is φ = 18058140.

The previous prime is 18071177. The next prime is 18071257. The reversal of 18071213 is 31217081.

It is a happy number.

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 18071213 - 2⁶ = 18071149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18071113) 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, 4181 + ... + 7322.

It is an arithmetic number, because the mean of its divisors is an integer number (4521072).

Almost surely, 2^18071213 is an apocalyptic number.

It is an amenable number.

18071213 is a deficient number, since it is larger than the sum of its proper divisors (13075).

18071213 is a wasteful number, since it uses less digits than its factorization.

18071213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13074.

The product of its (nonzero) digits is 336, while the sum is 23.

The square root of 18071213 is about 4251.0249352362. The cubic root of 18071213 is about 262.4192973381.

Adding to 18071213 its reverse (31217081), we get a palindrome (49288294).

The spelling of 18071213 in words is "eighteen million, seventy-one thousand, two hundred thirteen".