18711081 has 10 divisors (see below), whose sum is σ = 27951242. Its totient is φ = 12474000.

The previous prime is 18711059. The next prime is 18711089. The reversal of 18711081 is 18011781.

It can be written as a sum of positive squares in only one way, i.e., 10208025 + 8503056 = 3195^2 + 2916^2 .

It is not a de Polignac number, because 18711081 - 2¹⁹ = 18186793 is a prime.

It is a super-3 number, since 3×18711081³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18711089) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 115420 + ... + 115581.

Almost surely, 2^18711081 is an apocalyptic number.

It is an amenable number.

18711081 is a deficient number, since it is larger than the sum of its proper divisors (9240161).

18711081 is an equidigital number, since it uses as much as digits as its factorization.

18711081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231013 (or 231004 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 27.

The square root of 18711081 is about 4325.6307054579. The cubic root of 18711081 is about 265.4807033759.

The spelling of 18711081 in words is "eighteen million, seven hundred eleven thousand, eighty-one".