87240217 has 2 divisors, whose sum is σ = 87240218. Its totient is φ = 87240216.

The previous prime is 87240199. The next prime is 87240227. The reversal of 87240217 is 71204278.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75707401 + 11532816 = 8701^2 + 3396^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87240217 is a prime.

It is a super-2 number, since 2×87240217² = 15221710924414178, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (87240227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43620108 + 43620109.

It is an arithmetic number, because the mean of its divisors is an integer number (43620109).

Almost surely, 2^87240217 is an apocalyptic number.

It is an amenable number.

87240217 is a deficient number, since it is larger than the sum of its proper divisors (1).

87240217 is an equidigital number, since it uses as much as digits as its factorization.

87240217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6272, while the sum is 31.

The square root of 87240217 is about 9340.2471594707. The cubic root of 87240217 is about 443.5122084571.

The spelling of 87240217 in words is "eighty-seven million, two hundred forty thousand, two hundred seventeen".