85820909 has 2 divisors, whose sum is σ = 85820910. Its totient is φ = 85820908.

The previous prime is 85820897. The next prime is 85820923. The reversal of 85820909 is 90902858.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67732900 + 18088009 = 8230^2 + 4253^2 .

It is a cyclic number.

It is not a de Polignac number, because 85820909 - 2²⁰ = 84772333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85820209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42910454 + 42910455.

It is an arithmetic number, because the mean of its divisors is an integer number (42910455).

Almost surely, 2^85820909 is an apocalyptic number.

It is an amenable number.

85820909 is a deficient number, since it is larger than the sum of its proper divisors (1).

85820909 is an equidigital number, since it uses as much as digits as its factorization.

85820909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 41.

The square root of 85820909 is about 9263.9575236505. The cubic root of 85820909 is about 441.0938846431.

The spelling of 85820909 in words is "eighty-five million, eight hundred twenty thousand, nine hundred nine".