7843221 has 12 divisors (see below), whose sum is σ = 11499072. Its totient is φ = 5150376.

The previous prime is 7843201. The next prime is 7843229. The reversal of 7843221 is 1223487.

It is not a de Polignac number, because 7843221 - 2⁵ = 7843189 is a prime.

It is a super-2 number, since 2×7843221² = 123032231309682, which contains 22 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

7843221 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7843229) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5901 + ... + 7106.

It is an arithmetic number, because the mean of its divisors is an integer number (958256).

Almost surely, 2^7843221 is an apocalyptic number.

It is an amenable number.

7843221 is a deficient number, since it is larger than the sum of its proper divisors (3655851).

7843221 is a wasteful number, since it uses less digits than its factorization.

7843221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13080 (or 13077 counting only the distinct ones).

The product of its digits is 2688, while the sum is 27.

The square root of 7843221 is about 2800.5751195067. The cubic root of 7843221 is about 198.6848795794.

It can be divided in two parts, 784 and 3221, that added together give a triangular number (4005 = T₈₉).

The spelling of 7843221 in words is "seven million, eight hundred forty-three thousand, two hundred twenty-one".