2165071616525 has 6 divisors (see below), whose sum is σ = 2684688804522. Its totient is φ = 1732057293200.

The previous prime is 2165071616507. The next prime is 2165071616549. The reversal of 2165071616525 is 5256161705612.

It can be written as a sum of positive squares in 3 ways, for example, as 8629295236 + 2156442321289 = 92894^2 + 1468483^2 .

It is not a de Polignac number, because 2165071616525 - 2¹⁶ = 2165071550989 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2165071616525.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 43301432306 + ... + 43301432355.

It is an arithmetic number, because the mean of its divisors is an integer number (447448134087).

Almost surely, 2^{2165071616525} is an apocalyptic number.

2165071616525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

2165071616525 is a deficient number, since it is larger than the sum of its proper divisors (519617187997).

2165071616525 is an equidigital number, since it uses as much as digits as its factorization.

2165071616525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86602864671 (or 86602864666 counting only the distinct ones).

The product of its (nonzero) digits is 756000, while the sum is 47.

The spelling of 2165071616525 in words is "two trillion, one hundred sixty-five billion, seventy-one million, six hundred sixteen thousand, five hundred twenty-five".