18021271 has 2 divisors, whose sum is σ = 18021272. Its totient is φ = 18021270.

The previous prime is 18021247. The next prime is 18021281. The reversal of 18021271 is 17212081.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18021271 - 2⁵ = 18021239 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18021281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9010635 + 9010636.

It is an arithmetic number, because the mean of its divisors is an integer number (9010636).

Almost surely, 2^18021271 is an apocalyptic number.

18021271 is a deficient number, since it is larger than the sum of its proper divisors (1).

18021271 is an equidigital number, since it uses as much as digits as its factorization.

18021271 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 224, while the sum is 22.

The square root of 18021271 is about 4245.1467583583. The cubic root of 18021271 is about 262.1773317282.

The spelling of 18021271 in words is "eighteen million, twenty-one thousand, two hundred seventy-one".