85823821 has 2 divisors, whose sum is σ = 85823822. Its totient is φ = 85823820.

The previous prime is 85823813. The next prime is 85823873. The reversal of 85823821 is 12832858.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50552100 + 35271721 = 7110^2 + 5939^2 .

It is a cyclic number.

It is not a de Polignac number, because 85823821 - 2³ = 85823813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85823891) 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, 42911910 + 42911911.

It is an arithmetic number, because the mean of its divisors is an integer number (42911911).

Almost surely, 2^85823821 is an apocalyptic number.

It is an amenable number.

85823821 is a deficient number, since it is larger than the sum of its proper divisors (1).

85823821 is an equidigital number, since it uses as much as digits as its factorization.

85823821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30720, while the sum is 37.

The square root of 85823821 is about 9264.1146905681. The cubic root of 85823821 is about 441.0988735239.

It can be divided in two parts, 8582 and 3821, that added together give a triangular number (12403 = T₁₅₇).

The spelling of 85823821 in words is "eighty-five million, eight hundred twenty-three thousand, eight hundred twenty-one".