18027971 has 4 divisors (see below), whose sum is σ = 19414752. Its totient is φ = 16641192.

The previous prime is 18027959. The next prime is 18028013. The reversal of 18027971 is 17972081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17972081 = 19 ⋅945899.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18027971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18027271) 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 3 ways as a sum of consecutive naturals, for example, 693371 + ... + 693396.

It is an arithmetic number, because the mean of its divisors is an integer number (4853688).

Almost surely, 2^18027971 is an apocalyptic number.

18027971 is a deficient number, since it is larger than the sum of its proper divisors (1386781).

18027971 is a wasteful number, since it uses less digits than its factorization.

18027971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1386780.

The product of its (nonzero) digits is 7056, while the sum is 35.

The square root of 18027971 is about 4245.9358214650. The cubic root of 18027971 is about 262.2098187168.

The spelling of 18027971 in words is "eighteen million, twenty-seven thousand, nine hundred seventy-one".