2115285721 has 2 divisors, whose sum is σ = 2115285722. Its totient is φ = 2115285720.

The previous prime is 2115285701. The next prime is 2115285749. The reversal of 2115285721 is 1275825112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2101305600 + 13980121 = 45840^2 + 3739^2 .

It is a cyclic number.

It is not a de Polignac number, because 2115285721 - 2²⁹ = 1578414809 is a prime.

It is not a weakly prime, because it can be changed into another prime (2115285701) 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, 1057642860 + 1057642861.

It is an arithmetic number, because the mean of its divisors is an integer number (1057642861).

Almost surely, 2^2115285721 is an apocalyptic number.

It is an amenable number.

2115285721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2115285721 is an equidigital number, since it uses as much as digits as its factorization.

2115285721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11200, while the sum is 34.

The square root of 2115285721 is about 45992.2354425179. The cubic root of 2115285721 is about 1283.6787321423.

The spelling of 2115285721 in words is "two billion, one hundred fifteen million, two hundred eighty-five thousand, seven hundred twenty-one".