8221645 has 8 divisors (see below), whose sum is σ = 10206360. Its totient is φ = 6350400.

The previous prime is 8221627. The next prime is 8221651. The reversal of 8221645 is 5461228.

8221645 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 1283689 + 6937956 = 1133^2 + 2634^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 8221645 - 2¹¹ = 8219597 is a prime.

It is a super-3 number, since 3×8221645³ (a number of 22 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28206 + ... + 28495.

It is an arithmetic number, because the mean of its divisors is an integer number (1275795).

Almost surely, 2^8221645 is an apocalyptic number.

It is an amenable number.

8221645 is a deficient number, since it is larger than the sum of its proper divisors (1984715).

8221645 is a wasteful number, since it uses less digits than its factorization.

8221645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56735.

The product of its digits is 3840, while the sum is 28.

The square root of 8221645 is about 2867.3411028338. The cubic root of 8221645 is about 201.8302416532.

It can be divided in two parts, 822 and 1645, that multiplied together give a triangular number (1352190 = T₁₆₄₄).

The spelling of 8221645 in words is "eight million, two hundred twenty-one thousand, six hundred forty-five".