820873 has 2 divisors, whose sum is σ = 820874. Its totient is φ = 820872.

The previous prime is 820837. The next prime is 820891. The reversal of 820873 is 378028.

It is a happy number.

Together with previous prime (820837) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 710649 + 110224 = 843^2 + 332^2 .

It is a cyclic number.

It is not a de Polignac number, because 820873 - 2⁹ = 820361 is a prime.

It is a plaindrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (820073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410436 + 410437.

It is an arithmetic number, because the mean of its divisors is an integer number (410437).

2⁸²⁰⁸⁷³ is an apocalyptic number.

It is an amenable number.

820873 is a deficient number, since it is larger than the sum of its proper divisors (1).

820873 is an equidigital number, since it uses as much as digits as its factorization.

820873 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 820873 is about 906.0204191959. The cubic root of 820873 is about 93.6322206869.

It can be divided in two parts, 8208 and 73, that added together give a square (8281 = 91²).

The spelling of 820873 in words is "eight hundred twenty thousand, eight hundred seventy-three".