820723 has 2 divisors, whose sum is σ = 820724. Its totient is φ = 820722.

The previous prime is 820711. The next prime is 820733. The reversal of 820723 is 327028.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 820723 - 2⁵ = 820691 is a prime.

820723 is a lucky number.

It is a nialpdrome in base 7.

It is a junction number, because it is equal to n+sod(n) for n = 820694 and 820703.

It is not a weakly prime, because it can be changed into another prime (820733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410361 + 410362.

It is an arithmetic number, because the mean of its divisors is an integer number (410362).

2⁸²⁰⁷²³ is an apocalyptic number.

820723 is a deficient number, since it is larger than the sum of its proper divisors (1).

820723 is an equidigital number, since it uses as much as digits as its factorization.

820723 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 820723 is about 905.9376358227. The cubic root of 820723 is about 93.6265171296.

The spelling of 820723 in words is "eight hundred twenty thousand, seven hundred twenty-three".