802721 has 2 divisors, whose sum is σ = 802722. Its totient is φ = 802720.

The previous prime is 802709. The next prime is 802729. The reversal of 802721 is 127208.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 672400 + 130321 = 820^2 + 361^2 .

It is a cyclic number.

It is not a de Polignac number, because 802721 - 2¹⁴ = 786337 is a prime.

It is a super-2 number, since 2×802721² = 1288722007682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 802693 and 802702.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 802721.

It is not a weakly prime, because it can be changed into another prime (802729) 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, 401360 + 401361.

It is an arithmetic number, because the mean of its divisors is an integer number (401361).

2⁸⁰²⁷²¹ is an apocalyptic number.

It is an amenable number.

802721 is a deficient number, since it is larger than the sum of its proper divisors (1).

802721 is an equidigital number, since it uses as much as digits as its factorization.

802721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 802721 is about 895.9469850387. The cubic root of 802721 is about 92.9369055991.

Adding to 802721 its reverse (127208), we get a palindrome (929929).

The spelling of 802721 in words is "eight hundred two thousand, seven hundred twenty-one".