85821811 has 4 divisors (see below), whose sum is σ = 86623992. Its totient is φ = 85019632.

The previous prime is 85821781. The next prime is 85821829. The reversal of 85821811 is 11812858.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 85821811 - 2⁵ = 85821779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (85821881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 400930 + ... + 401143.

It is an arithmetic number, because the mean of its divisors is an integer number (21655998).

Almost surely, 2^85821811 is an apocalyptic number.

85821811 is a deficient number, since it is larger than the sum of its proper divisors (802181).

85821811 is a wasteful number, since it uses less digits than its factorization.

85821811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 802180.

The product of its digits is 5120, while the sum is 34.

The square root of 85821811 is about 9264.0062068200. The cubic root of 85821811 is about 441.0954299747.

The spelling of 85821811 in words is "eighty-five million, eight hundred twenty-one thousand, eight hundred eleven".