2172105 has 48 divisors (see below), whose sum is σ = 4193280. Its totient is φ = 1033344.

The previous prime is 2172091. The next prime is 2172109. The reversal of 2172105 is 5012712.

It is not a de Polignac number, because 2172105 - 2⁴ = 2172089 is a prime.

It is an Ulam number.

2172105 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2172109) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 27456 + ... + 27534.

It is an arithmetic number, because the mean of its divisors is an integer number (87360).

2^2172105 is an apocalyptic number.

It is an amenable number.

2172105 is a deficient number, since it is larger than the sum of its proper divisors (2021175).

2172105 is a wasteful number, since it uses less digits than its factorization.

2172105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 2172105 is about 1473.8062966347. The cubic root of 2172105 is about 129.5071079316.

Adding to 2172105 its reverse (5012712), we get a palindrome (7184817).

The spelling of 2172105 in words is "two million, one hundred seventy-two thousand, one hundred five".