2161103125 has 12 divisors (see below), whose sum is σ = 2701209924. Its totient is φ = 1728880000.

The previous prime is 2161103107. The next prime is 2161103129. The reversal of 2161103125 is 5213011612.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 1992908164 + 168194961 = 44642^2 + 12969^2 .

It is not a de Polignac number, because 2161103125 - 2³¹ = 13619477 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2161103096 and 2161103105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161103129) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 342652 + ... + 348901.

It is an arithmetic number, because the mean of its divisors is an integer number (225100827).

Almost surely, 2^2161103125 is an apocalyptic number.

2161103125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

2161103125 is a deficient number, since it is larger than the sum of its proper divisors (540106799).

2161103125 is an frugal number, since it uses more digits than its factorization.

2161103125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 691578 (or 691558 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 2161103125 is about 46487.6663750720. Note that the first 3 decimals coincide. The cubic root of 2161103125 is about 1292.8808331209.

Adding to 2161103125 its reverse (5213011612), we get a palindrome (7374114737).

The spelling of 2161103125 in words is "two billion, one hundred sixty-one million, one hundred three thousand, one hundred twenty-five".