87181 has 2 divisors, whose sum is σ = 87182. Its totient is φ = 87180.

The previous prime is 87179. The next prime is 87187. The reversal of 87181 is 18178.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84681 + 2500 = 291^2 + 50^2 .

It is a cyclic number.

It is not a de Polignac number, because 87181 - 2¹ = 87179 is a prime.

It is a super-2 number, since 2×87181² = 15201053522, which contains 22 as substring.

Together with 87179, it forms a pair of twin primes.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43590 + 43591.

It is an arithmetic number, because the mean of its divisors is an integer number (43591).

2⁸⁷¹⁸¹ is an apocalyptic number.

It is an amenable number.

87181 is a deficient number, since it is larger than the sum of its proper divisors (1).

87181 is an equidigital number, since it uses as much as digits as its factorization.

87181 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 87181 is about 295.2642883926. The cubic root of 87181 is about 44.3411836526.

The spelling of 87181 in words is "eighty-seven thousand, one hundred eighty-one".