87180209 has 2 divisors, whose sum is σ = 87180210. Its totient is φ = 87180208.

The previous prime is 87180187. The next prime is 87180211. The reversal of 87180209 is 90208178.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44930209 + 42250000 = 6703^2 + 6500^2 .

It is a cyclic number.

It is not a de Polignac number, because 87180209 - 2¹² = 87176113 is a prime.

It is a Sophie Germain prime.

Together with 87180211, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (87180809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43590104 + 43590105.

It is an arithmetic number, because the mean of its divisors is an integer number (43590105).

Almost surely, 2^87180209 is an apocalyptic number.

It is an amenable number.

87180209 is a deficient number, since it is larger than the sum of its proper divisors (1).

87180209 is an equidigital number, since it uses as much as digits as its factorization.

87180209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 87180209 is about 9337.0342721873. The cubic root of 87180209 is about 443.4104954856.

The spelling of 87180209 in words is "eighty-seven million, one hundred eighty thousand, two hundred nine".