85247821 has 6 divisors (see below), whose sum is σ = 89115950. Its totient is φ = 81540888.

The previous prime is 85247777. The next prime is 85247831. The reversal of 85247821 is 12874258.

It can be written as a sum of positive squares in only one way, i.e., 53494596 + 31753225 = 7314^2 + 5635^2 .

It is a de Polignac number, because none of the positive numbers 2^k-85247821 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 (85247831) 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 5 ways as a sum of consecutive naturals, for example, 80046 + ... + 81103.

Almost surely, 2^85247821 is an apocalyptic number.

It is an amenable number.

85247821 is a deficient number, since it is larger than the sum of its proper divisors (3868129).

85247821 is a wasteful number, since it uses less digits than its factorization.

85247821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161195 (or 161172 counting only the distinct ones).

The product of its digits is 35840, while the sum is 37.

The square root of 85247821 is about 9232.9746560900. The cubic root of 85247821 is about 440.1098572109.

It can be divided in two parts, 85247 and 821, that added together give a palindrome (86068).

The spelling of 85247821 in words is "eighty-five million, two hundred forty-seven thousand, eight hundred twenty-one".