820331 has 2 divisors, whose sum is σ = 820332. Its totient is φ = 820330.

The previous prime is 820321. The next prime is 820333. The reversal of 820331 is 133028.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 820331 - 2¹⁰ = 819307 is a prime.

It is a super-2 number, since 2×820331² = 1345885899122, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 820333, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 12.

It is a nialpdrome in base 7.

It is not a weakly prime, because it can be changed into another prime (820333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410165 + 410166.

It is an arithmetic number, because the mean of its divisors is an integer number (410166).

2⁸²⁰³³¹ is an apocalyptic number.

820331 is a deficient number, since it is larger than the sum of its proper divisors (1).

820331 is an equidigital number, since it uses as much as digits as its factorization.

820331 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 820331 is about 905.7212595495. The cubic root of 820331 is about 93.6116085512.

Adding to 820331 its reverse (133028), we get a palindrome (953359).

The spelling of 820331 in words is "eight hundred twenty thousand, three hundred thirty-one".