85287821 has 4 divisors (see below), whose sum is σ = 86686044. Its totient is φ = 83889600.

The previous prime is 85287817. The next prime is 85287857. The reversal of 85287821 is 12878258.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8094025 + 77193796 = 2845^2 + 8786^2 .

It is a cyclic number.

It is not a de Polignac number, because 85287821 - 2² = 85287817 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85286821) 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 in 3 ways as a sum of consecutive naturals, for example, 699020 + ... + 699141.

It is an arithmetic number, because the mean of its divisors is an integer number (21671511).

Almost surely, 2^85287821 is an apocalyptic number.

It is an amenable number.

85287821 is a deficient number, since it is larger than the sum of its proper divisors (1398223).

85287821 is a wasteful number, since it uses less digits than its factorization.

85287821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1398222.

The product of its digits is 71680, while the sum is 41.

The square root of 85287821 is about 9235.1405511773. The cubic root of 85287821 is about 440.1786825930.

The spelling of 85287821 in words is "eighty-five million, two hundred eighty-seven thousand, eight hundred twenty-one".