797821 has 4 divisors (see below), whose sum is σ = 808000. Its totient is φ = 787644.

The previous prime is 797813. The next prime is 797833. The reversal of 797821 is 128797.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 797821 - 2³ = 797813 is a prime.

It is a Duffinian number.

797821 is a modest number, since divided by 7821 gives 79 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (797851) 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 3 ways as a sum of consecutive naturals, for example, 4971 + ... + 5128.

It is an arithmetic number, because the mean of its divisors is an integer number (202000).

2⁷⁹⁷⁸²¹ is an apocalyptic number.

It is an amenable number.

797821 is a deficient number, since it is larger than the sum of its proper divisors (10179).

797821 is a wasteful number, since it uses less digits than its factorization.

797821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10178.

The product of its digits is 7056, while the sum is 34.

The square root of 797821 is about 893.2082623890. The cubic root of 797821 is about 92.7474165166.

The spelling of 797821 in words is "seven hundred ninety-seven thousand, eight hundred twenty-one".