820961 has 4 divisors (see below), whose sum is σ = 849300. Its totient is φ = 792624.

The previous prime is 820957. The next prime is 820969. The reversal of 820961 is 169028.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 390625 + 430336 = 625^2 + 656^2 .

It is a cyclic number.

It is not a de Polignac number, because 820961 - 2² = 820957 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 820961.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 820961.

It is not an unprimeable number, because it can be changed into a prime (820969) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14126 + ... + 14183.

It is an arithmetic number, because the mean of its divisors is an integer number (212325).

2⁸²⁰⁹⁶¹ is an apocalyptic number.

It is an amenable number.

820961 is a deficient number, since it is larger than the sum of its proper divisors (28339).

820961 is a wasteful number, since it uses less digits than its factorization.

820961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28338.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 820961 is about 906.0689819214. The cubic root of 820961 is about 93.6355664505.

Adding to 820961 its reverse (169028), we get a palindrome (989989).

The spelling of 820961 in words is "eight hundred twenty thousand, nine hundred sixty-one".