879639521 has 2 divisors, whose sum is σ = 879639522. Its totient is φ = 879639520.

The previous prime is 879639499. The next prime is 879639533. The reversal of 879639521 is 125936978.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 470022400 + 409617121 = 21680^2 + 20239^2 .

It is a cyclic number.

It is not a de Polignac number, because 879639521 - 2⁶ = 879639457 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 879639521.

It is not a weakly prime, because it can be changed into another prime (879639821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 439819760 + 439819761.

It is an arithmetic number, because the mean of its divisors is an integer number (439819761).

Almost surely, 2^879639521 is an apocalyptic number.

It is an amenable number.

879639521 is a deficient number, since it is larger than the sum of its proper divisors (1).

879639521 is an equidigital number, since it uses as much as digits as its factorization.

879639521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 816480, while the sum is 50.

The square root of 879639521 is about 29658.7174537268. The cubic root of 879639521 is about 958.1531045842.

The spelling of 879639521 in words is "eight hundred seventy-nine million, six hundred thirty-nine thousand, five hundred twenty-one".