879721 has 2 divisors, whose sum is σ = 879722. Its totient is φ = 879720.

The previous prime is 879713. The next prime is 879743. The reversal of 879721 is 127978.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 746496 + 133225 = 864^2 + 365^2 .

It is a cyclic number.

It is not a de Polignac number, because 879721 - 2³ = 879713 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (879701) 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, 439860 + 439861.

It is an arithmetic number, because the mean of its divisors is an integer number (439861).

2⁸⁷⁹⁷²¹ is an apocalyptic number.

It is an amenable number.

879721 is a deficient number, since it is larger than the sum of its proper divisors (1).

879721 is an equidigital number, since it uses as much as digits as its factorization.

879721 is an odious number, because the sum of its binary digits is odd.

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

The square root of 879721 is about 937.9344326764. The cubic root of 879721 is about 95.8182687516.

It can be divided in two parts, 879 and 721, that added together give a square (1600 = 40²).

The spelling of 879721 in words is "eight hundred seventy-nine thousand, seven hundred twenty-one".