2165204257 has 2 divisors, whose sum is σ = 2165204258. Its totient is φ = 2165204256.

The previous prime is 2165204203. The next prime is 2165204281. The reversal of 2165204257 is 7524025612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2055352896 + 109851361 = 45336^2 + 10481^2 .

It is a cyclic number.

It is not a de Polignac number, because 2165204257 - 2³¹ = 17720609 is a prime.

It is not a weakly prime, because it can be changed into another prime (2165204297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1082602128 + 1082602129.

It is an arithmetic number, because the mean of its divisors is an integer number (1082602129).

Almost surely, 2^2165204257 is an apocalyptic number.

It is an amenable number.

2165204257 is a deficient number, since it is larger than the sum of its proper divisors (1).

2165204257 is an equidigital number, since it uses as much as digits as its factorization.

2165204257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 33600, while the sum is 34.

The square root of 2165204257 is about 46531.7553612584. The cubic root of 2165204257 is about 1293.6981509650.

Adding to 2165204257 its reverse (7524025612), we get a palindrome (9689229869).

The spelling of 2165204257 in words is "two billion, one hundred sixty-five million, two hundred four thousand, two hundred fifty-seven".