2185172121 has 64 divisors (see below), whose sum is σ = 3454617600. Its totient is φ = 1214323200.

The previous prime is 2185172047. The next prime is 2185172137. The reversal of 2185172121 is 1212715812.

It is not a de Polignac number, because 2185172121 - 2¹¹ = 2185170073 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2185172221) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4292815 + ... + 4293323.

It is an arithmetic number, because the mean of its divisors is an integer number (53978400).

Almost surely, 2^2185172121 is an apocalyptic number.

It is an amenable number.

2185172121 is a deficient number, since it is larger than the sum of its proper divisors (1269445479).

2185172121 is a wasteful number, since it uses less digits than its factorization.

2185172121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 750.

The product of its digits is 2240, while the sum is 30.

The square root of 2185172121 is about 46745.8246370732. The cubic root of 2185172121 is about 1297.6628859106.

Adding to 2185172121 its reverse (1212715812), we get a palindrome (3397887933).

The spelling of 2185172121 in words is "two billion, one hundred eighty-five million, one hundred seventy-two thousand, one hundred twenty-one".