85821091 has 2 divisors, whose sum is σ = 85821092. Its totient is φ = 85821090.

The previous prime is 85821089. The next prime is 85821137. The reversal of 85821091 is 19012858.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 85821091 - 2¹ = 85821089 is a prime.

Together with 85821089, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (85821191) 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, 42910545 + 42910546.

It is an arithmetic number, because the mean of its divisors is an integer number (42910546).

Almost surely, 2^85821091 is an apocalyptic number.

85821091 is a deficient number, since it is larger than the sum of its proper divisors (1).

85821091 is an equidigital number, since it uses as much as digits as its factorization.

85821091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 85821091 is about 9263.9673466609. The cubic root of 85821091 is about 441.0941964514.

The spelling of 85821091 in words is "eighty-five million, eight hundred twenty-one thousand, ninety-one".