17881 has 2 divisors, whose sum is σ = 17882. Its totient is φ = 17880.

The previous prime is 17863. The next prime is 17891. The reversal of 17881 is 18871.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14400 + 3481 = 120^2 + 59^2 .

It is a cyclic number.

It is not a de Polignac number, because 17881 - 2¹³ = 9689 is a prime.

It is a super-2 number, since 2×17881² = 639460322, which contains 22 as substring.

It is a nialpdrome in base 12.

It is not a weakly prime, because it can be changed into another prime (17851) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8940 + 8941.

It is an arithmetic number, because the mean of its divisors is an integer number (8941).

2¹⁷⁸⁸¹ is an apocalyptic number.

It is an amenable number.

17881 is a deficient number, since it is larger than the sum of its proper divisors (1).

17881 is an equidigital number, since it uses as much as digits as its factorization.

17881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 448, while the sum is 25.

The square root of 17881 is about 133.7198564163. The cubic root of 17881 is about 26.1495328261.

Subtracting 17881 from its reverse (18871), we obtain a triangular number (990 = T₄₄).

It can be divided in two parts, 17 and 881, that added together give a palindrome (898).

The spelling of 17881 in words is "seventeen thousand, eight hundred eighty-one".