6821231 has 2 divisors, whose sum is σ = 6821232. Its totient is φ = 6821230.

The previous prime is 6821207. The next prime is 6821239. The reversal of 6821231 is 1321286.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6821231 - 2¹⁰ = 6820207 is a prime.

It is a super-2 number, since 2×6821231² = 93058384710722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 6821197 and 6821206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6821239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3410615 + 3410616.

It is an arithmetic number, because the mean of its divisors is an integer number (3410616).

Almost surely, 2^6821231 is an apocalyptic number.

6821231 is a deficient number, since it is larger than the sum of its proper divisors (1).

6821231 is an equidigital number, since it uses as much as digits as its factorization.

6821231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 576, while the sum is 23.

The square root of 6821231 is about 2611.7486479369. The cubic root of 6821231 is about 189.6506136869.

Subtracting from 6821231 its reverse (1321286), we obtain a palindrome (5499945).

The spelling of 6821231 in words is "six million, eight hundred twenty-one thousand, two hundred thirty-one".