2173113721 has 2 divisors, whose sum is σ = 2173113722. Its totient is φ = 2173113720.

The previous prime is 2173113647. The next prime is 2173113731. The reversal of 2173113721 is 1273113712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2133423721 + 39690000 = 46189^2 + 6300^2 .

It is a cyclic number.

It is not a de Polignac number, because 2173113721 - 2²³ = 2164725113 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2173113721.

It is not a weakly prime, because it can be changed into another prime (2173113731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1086556860 + 1086556861.

It is an arithmetic number, because the mean of its divisors is an integer number (1086556861).

Almost surely, 2^2173113721 is an apocalyptic number.

It is an amenable number.

2173113721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2173113721 is an equidigital number, since it uses as much as digits as its factorization.

2173113721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1764, while the sum is 28.

The square root of 2173113721 is about 46616.6678453104. The cubic root of 2173113721 is about 1295.2715243872.

Subtracting from 2173113721 its reverse (1273113712), we obtain a palindrome (900000009).

The spelling of 2173113721 in words is "two billion, one hundred seventy-three million, one hundred thirteen thousand, seven hundred twenty-one".