85867609 has 2 divisors, whose sum is σ = 85867610. Its totient is φ = 85867608.

The previous prime is 85867591. The next prime is 85867619. The reversal of 85867609 is 90676858.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 73051209 + 12816400 = 8547^2 + 3580^2 .

It is a cyclic number.

It is not a de Polignac number, because 85867609 - 2⁹ = 85867097 is a prime.

It is not a weakly prime, because it can be changed into another prime (85867619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42933804 + 42933805.

It is an arithmetic number, because the mean of its divisors is an integer number (42933805).

Almost surely, 2^85867609 is an apocalyptic number.

It is an amenable number.

85867609 is a deficient number, since it is larger than the sum of its proper divisors (1).

85867609 is an equidigital number, since it uses as much as digits as its factorization.

85867609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 725760, while the sum is 49.

The square root of 85867609 is about 9266.4777019103. The cubic root of 85867609 is about 441.1738781606.

Subtracting 85867609 from its reverse (90676858), we obtain a square (4809249 = 2193²).

The spelling of 85867609 in words is "eighty-five million, eight hundred sixty-seven thousand, six hundred nine".