871520921 has 2 divisors, whose sum is σ = 871520922. Its totient is φ = 871520920.

The previous prime is 871520917. The next prime is 871520933. The reversal of 871520921 is 129025178.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 499030921 + 372490000 = 22339^2 + 19300^2 .

It is a cyclic number.

It is not a de Polignac number, because 871520921 - 2² = 871520917 is a prime.

It is not a weakly prime, because it can be changed into another prime (871520971) 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, 435760460 + 435760461.

It is an arithmetic number, because the mean of its divisors is an integer number (435760461).

Almost surely, 2^871520921 is an apocalyptic number.

It is an amenable number.

871520921 is a deficient number, since it is larger than the sum of its proper divisors (1).

871520921 is an equidigital number, since it uses as much as digits as its factorization.

871520921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 871520921 is about 29521.5331749555. The cubic root of 871520921 is about 955.1962430334.

The spelling of 871520921 in words is "eight hundred seventy-one million, five hundred twenty thousand, nine hundred twenty-one".