87091181 has 2 divisors, whose sum is σ = 87091182. Its totient is φ = 87091180.

The previous prime is 87091163. The next prime is 87091201. The reversal of 87091181 is 18119078.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 82537225 + 4553956 = 9085^2 + 2134^2 .

It is a cyclic number.

It is not a de Polignac number, because 87091181 - 2¹⁴ = 87074797 is a prime.

It is a super-2 number, since 2×87091181² = 15169747615949522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87091111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43545590 + 43545591.

It is an arithmetic number, because the mean of its divisors is an integer number (43545591).

Almost surely, 2^87091181 is an apocalyptic number.

It is an amenable number.

87091181 is a deficient number, since it is larger than the sum of its proper divisors (1).

87091181 is an equidigital number, since it uses as much as digits as its factorization.

87091181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 35.

The square root of 87091181 is about 9332.2655877338. The cubic root of 87091181 is about 443.2595078733.

The spelling of 87091181 in words is "eighty-seven million, ninety-one thousand, one hundred eighty-one".