2126651665 has 16 divisors (see below), whose sum is σ = 2691515520. Its totient is φ = 1608647040.

The previous prime is 2126651663. The next prime is 2126651671. The reversal of 2126651665 is 5661566212.

It is not a de Polignac number, because 2126651665 - 2¹ = 2126651663 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2126651663) 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 in 15 ways as a sum of consecutive naturals, for example, 28012 + ... + 70978.

It is an arithmetic number, because the mean of its divisors is an integer number (168219720).

Almost surely, 2^2126651665 is an apocalyptic number.

It is an amenable number.

2126651665 is a deficient number, since it is larger than the sum of its proper divisors (564863855).

2126651665 is a wasteful number, since it uses less digits than its factorization.

2126651665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43512.

The product of its digits is 129600, while the sum is 40.

The square root of 2126651665 is about 46115.6336289549. The cubic root of 2126651665 is about 1285.9737989352.

The spelling of 2126651665 in words is "two billion, one hundred twenty-six million, six hundred fifty-one thousand, six hundred sixty-five".