876721 has 2 divisors, whose sum is σ = 876722. Its totient is φ = 876720.

The previous prime is 876719. The next prime is 876731. The reversal of 876721 is 127678.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 876096 + 625 = 936^2 + 25^2 .

It is a cyclic number.

It is not a de Polignac number, because 876721 - 2¹ = 876719 is a prime.

Together with 876719, it forms a pair of twin primes.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

876721 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (876731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 438360 + 438361.

It is an arithmetic number, because the mean of its divisors is an integer number (438361).

2⁸⁷⁶⁷²¹ is an apocalyptic number.

It is an amenable number.

876721 is a deficient number, since it is larger than the sum of its proper divisors (1).

876721 is an equidigital number, since it uses as much as digits as its factorization.

876721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4704, while the sum is 31.

The square root of 876721 is about 936.3338079980. Note that the first 3 decimals coincide. The cubic root of 876721 is about 95.7092257771.

It can be divided in two parts, 8 and 76721, that added together give a square (76729 = 277²).

The spelling of 876721 in words is "eight hundred seventy-six thousand, seven hundred twenty-one".