2161113525 has 36 divisors (see below), whose sum is σ = 4098495492. Its totient is φ = 1084792320.

The previous prime is 2161113503. The next prime is 2161113527. The reversal of 2161113525 is 5253111612.

2161113525 is a `hidden beast` number, since 21 + 6 + 1 + 113 + 525 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 300571569 + 1860541956 = 17337^2 + 43134^2 .

It is not a de Polignac number, because 2161113525 - 2¹³ = 2161105333 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161113527) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 278674 + ... + 286323.

It is an arithmetic number, because the mean of its divisors is an integer number (113847097).

Almost surely, 2^2161113525 is an apocalyptic number.

2161113525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

2161113525 is a deficient number, since it is larger than the sum of its proper divisors (1937381967).

2161113525 is a wasteful number, since it uses less digits than its factorization.

2161113525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 565030 (or 565022 counting only the distinct ones).

The product of its digits is 1800, while the sum is 27.

The square root of 2161113525 is about 46487.7782325634. The cubic root of 2161113525 is about 1292.8829070523.

The spelling of 2161113525 in words is "two billion, one hundred sixty-one million, one hundred thirteen thousand, five hundred twenty-five".