8287821 has 6 divisors (see below), whose sum is σ = 11971310. Its totient is φ = 5525208.

The previous prime is 8287817. The next prime is 8287831. The reversal of 8287821 is 1287828.

It can be written as a sum of positive squares in only one way, i.e., 4247721 + 4040100 = 2061^2 + 2010^2 .

It is not a de Polignac number, because 8287821 - 2² = 8287817 is a prime.

It is a Duffinian number.

8287821 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8287801) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 460426 + ... + 460443.

Almost surely, 2^8287821 is an apocalyptic number.

It is an amenable number.

8287821 is a deficient number, since it is larger than the sum of its proper divisors (3683489).

8287821 is a wasteful number, since it uses less digits than its factorization.

8287821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 920875 (or 920872 counting only the distinct ones).

The product of its digits is 14336, while the sum is 36.

The square root of 8287821 is about 2878.8575859184. The cubic root of 8287821 is about 202.3703056131.

It can be divided in two parts, 828 and 7821, that added together give a square (8649 = 93²).

The spelling of 8287821 in words is "eight million, two hundred eighty-seven thousand, eight hundred twenty-one".