7829221 has 2 divisors, whose sum is σ = 7829222. Its totient is φ = 7829220.

The previous prime is 7829219. The next prime is 7829233. The reversal of 7829221 is 1229287.

7829221 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6964321 + 864900 = 2639^2 + 930^2 .

It is a cyclic number.

It is not a de Polignac number, because 7829221 - 2¹ = 7829219 is a prime.

It is a super-2 number, since 2×7829221² = 122593402933682, which contains 22 as substring.

Together with 7829219, it forms a pair of twin primes.

7829221 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7829201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3914610 + 3914611.

It is an arithmetic number, because the mean of its divisors is an integer number (3914611).

Almost surely, 2^7829221 is an apocalyptic number.

It is an amenable number.

7829221 is a deficient number, since it is larger than the sum of its proper divisors (1).

7829221 is an equidigital number, since it uses as much as digits as its factorization.

7829221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 31.

The square root of 7829221 is about 2798.0745165202. The cubic root of 7829221 is about 198.5665929305.

The spelling of 7829221 in words is "seven million, eight hundred twenty-nine thousand, two hundred twenty-one".