821197 has 8 divisors (see below), whose sum is σ = 891800. Its totient is φ = 751680.

The previous prime is 821173. The next prime is 821207. The reversal of 821197 is 791128.

It can be written as a sum of positive squares in 4 ways, for example, as 361 + 820836 = 19^2 + 906^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 821197 - 2⁷ = 821069 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821147) 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 in 7 ways as a sum of consecutive naturals, for example, 2179 + ... + 2527.

It is an arithmetic number, because the mean of its divisors is an integer number (111475).

2⁸²¹¹⁹⁷ is an apocalyptic number.

It is an amenable number.

821197 is a deficient number, since it is larger than the sum of its proper divisors (70603).

821197 is a wasteful number, since it uses less digits than its factorization.

821197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543.

The product of its digits is 1008, while the sum is 28.

The square root of 821197 is about 906.1992054731. The cubic root of 821197 is about 93.6445379999.

The spelling of 821197 in words is "eight hundred twenty-one thousand, one hundred ninety-seven".