18213131 has 8 divisors (see below), whose sum is σ = 18961680. Its totient is φ = 17472672.

The previous prime is 18213119. The next prime is 18213149. The reversal of 18213131 is 13131281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18213131 - 2⁶ = 18213067 is a prime.

It is a super-2 number, since 2×18213131² = 663436281646322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18213101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2801 + ... + 6653.

It is an arithmetic number, because the mean of its divisors is an integer number (2370210).

Almost surely, 2^18213131 is an apocalyptic number.

18213131 is a deficient number, since it is larger than the sum of its proper divisors (748549).

18213131 is a wasteful number, since it uses less digits than its factorization.

18213131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4045.

The product of its digits is 144, while the sum is 20.

The square root of 18213131 is about 4267.6845009911. The cubic root of 18213131 is about 263.1044561871.

The spelling of 18213131 in words is "eighteen million, two hundred thirteen thousand, one hundred thirty-one".