18027881 has 2 divisors, whose sum is σ = 18027882. Its totient is φ = 18027880.

The previous prime is 18027869. The next prime is 18027887. The reversal of 18027881 is 18872081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15531481 + 2496400 = 3941^2 + 1580^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18027881 is a prime.

It is a super-2 number, since 2×18027881² = 650008986700322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18027887) 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 as a sum of consecutive naturals, namely, 9013940 + 9013941.

It is an arithmetic number, because the mean of its divisors is an integer number (9013941).

Almost surely, 2^18027881 is an apocalyptic number.

It is an amenable number.

18027881 is a deficient number, since it is larger than the sum of its proper divisors (1).

18027881 is an equidigital number, since it uses as much as digits as its factorization.

18027881 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7168, while the sum is 35.

The square root of 18027881 is about 4245.9252230815. The cubic root of 18027881 is about 262.2093823777.

The spelling of 18027881 in words is "eighteen million, twenty-seven thousand, eight hundred eighty-one".