2126501665 has 8 divisors (see below), whose sum is σ = 2552128488. Its totient is φ = 1700983680.

The previous prime is 2126501651. The next prime is 2126501693. The reversal of 2126501665 is 5661056212.

It can be written as a sum of positive squares in 4 ways, for example, as 1164447376 + 962054289 = 34124^2 + 31017^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2126501665 - 2⁵ = 2126501633 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2126501665.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24829 + ... + 69781.

It is an arithmetic number, because the mean of its divisors is an integer number (319016061).

Almost surely, 2^2126501665 is an apocalyptic number.

It is an amenable number.

2126501665 is a deficient number, since it is larger than the sum of its proper divisors (425626823).

2126501665 is an equidigital number, since it uses as much as digits as its factorization.

2126501665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54419.

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

The square root of 2126501665 is about 46114.0072537618. The cubic root of 2126501665 is about 1285.9435635173.

Adding to 2126501665 its reverse (5661056212), we get a palindrome (7787557877).

The spelling of 2126501665 in words is "two billion, one hundred twenty-six million, five hundred one thousand, six hundred sixty-five".