18021131 has 2 divisors, whose sum is σ = 18021132. Its totient is φ = 18021130.

The previous prime is 18021083. The next prime is 18021187. The reversal of 18021131 is 13112081.

It is a weak prime.

It is an emirp because it is prime and its reverse (13112081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18021131 - 2¹⁴ = 18004747 is a prime.

It is a super-2 number, since 2×18021131² = 649522325038322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18029131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9010565 + 9010566.

It is an arithmetic number, because the mean of its divisors is an integer number (9010566).

Almost surely, 2^18021131 is an apocalyptic number.

18021131 is a deficient number, since it is larger than the sum of its proper divisors (1).

18021131 is an equidigital number, since it uses as much as digits as its factorization.

18021131 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 17.

The square root of 18021131 is about 4245.1302689081. The cubic root of 18021131 is about 262.1766528097.

The spelling of 18021131 in words is "eighteen million, twenty-one thousand, one hundred thirty-one".