2099175721 has 2 divisors, whose sum is σ = 2099175722. Its totient is φ = 2099175720.

The previous prime is 2099175719. The next prime is 2099175779. The reversal of 2099175721 is 1275719902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1194670096 + 904505625 = 34564^2 + 30075^2 .

It is a cyclic number.

It is not a de Polignac number, because 2099175721 - 2¹ = 2099175719 is a prime.

Together with 2099175719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2099170721) 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, 1049587860 + 1049587861.

It is an arithmetic number, because the mean of its divisors is an integer number (1049587861).

Almost surely, 2^2099175721 is an apocalyptic number.

It is an amenable number.

2099175721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2099175721 is an equidigital number, since it uses as much as digits as its factorization.

2099175721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 79380, while the sum is 43.

The square root of 2099175721 is about 45816.7624456377. The cubic root of 2099175721 is about 1280.4115947256.

The spelling of 2099175721 in words is "two billion, ninety-nine million, one hundred seventy-five thousand, seven hundred twenty-one".