85809569 has 2 divisors, whose sum is σ = 85809570. Its totient is φ = 85809568.

The previous prime is 85809551. The next prime is 85809571. The reversal of 85809569 is 96590858.

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., 85803169 + 6400 = 9263^2 + 80^2 .

It is a cyclic number.

It is not a de Polignac number, because 85809569 - 2⁸ = 85809313 is a prime.

It is a super-2 number, since 2×85809569² = 14726564263931522, which contains 22 as substring.

Together with 85809571, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 11.

It is not a weakly prime, because it can be changed into another prime (85809469) 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, 42904784 + 42904785.

It is an arithmetic number, because the mean of its divisors is an integer number (42904785).

Almost surely, 2^85809569 is an apocalyptic number.

It is an amenable number.

85809569 is a deficient number, since it is larger than the sum of its proper divisors (1).

85809569 is an equidigital number, since it uses as much as digits as its factorization.

85809569 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 777600, while the sum is 50.

The square root of 85809569 is about 9263.3454539923. The cubic root of 85809569 is about 441.0744557143.

The spelling of 85809569 in words is "eighty-five million, eight hundred nine thousand, five hundred sixty-nine".