2165501266 has 4 divisors (see below), whose sum is σ = 3248251902. Its totient is φ = 1082750632.

The previous prime is 2165501263. The next prime is 2165501279. The reversal of 2165501266 is 6621055612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 2063794041 + 101707225 = 45429^2 + 10085^2 .

It is not an unprimeable number, because it can be changed into a prime (2165501263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 541375315 + ... + 541375318.

Almost surely, 2^2165501266 is an apocalyptic number.

2165501266 is a deficient number, since it is larger than the sum of its proper divisors (1082750636).

2165501266 is a wasteful number, since it uses less digits than its factorization.

2165501266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1082750635.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 2165501266 is about 46534.9467174939. The cubic root of 2165501266 is about 1293.7573020320.

Adding to 2165501266 its reverse (6621055612), we get a palindrome (8786556878).

The spelling of 2165501266 in words is "two billion, one hundred sixty-five million, five hundred one thousand, two hundred sixty-six".