87309181 has 2 divisors, whose sum is σ = 87309182. Its totient is φ = 87309180.

The previous prime is 87309149. The next prime is 87309191. The reversal of 87309181 is 18190378.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80371225 + 6937956 = 8965^2 + 2634^2 .

It is a cyclic number.

It is not a de Polignac number, because 87309181 - 2⁵ = 87309149 is a prime.

It is a super-2 number, since 2×87309181² = 15245786173781522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 87309181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87309191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43654590 + 43654591.

It is an arithmetic number, because the mean of its divisors is an integer number (43654591).

Almost surely, 2^87309181 is an apocalyptic number.

It is an amenable number.

87309181 is a deficient number, since it is larger than the sum of its proper divisors (1).

87309181 is an equidigital number, since it uses as much as digits as its factorization.

87309181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 87309181 is about 9343.9381954292. The cubic root of 87309181 is about 443.6290441741.

The spelling of 87309181 in words is "eighty-seven million, three hundred nine thousand, one hundred eighty-one".