18212931 has 20 divisors (see below), whose sum is σ = 29681784. Its totient is φ = 11037600.

The previous prime is 18212893. The next prime is 18212947. The reversal of 18212931 is 13921281.

It is not a de Polignac number, because 18212931 - 2¹⁷ = 18081859 is a prime.

It is a super-2 number, since 2×18212931² = 663421711221522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 18212895 and 18212904.

It is not an unprimeable number, because it can be changed into a prime (18212981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 9330 + ... + 11111.

Almost surely, 2^18212931 is an apocalyptic number.

18212931 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18212931 is a deficient number, since it is larger than the sum of its proper divisors (11468853).

18212931 is a wasteful number, since it uses less digits than its factorization.

18212931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20464 (or 20455 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 18212931 is about 4267.6610690166. The cubic root of 18212931 is about 263.1034931258.

The spelling of 18212931 in words is "eighteen million, two hundred twelve thousand, nine hundred thirty-one".