2172645 has 12 divisors (see below), whose sum is σ = 3765996. Its totient is φ = 1158720.

The previous prime is 2172641. The next prime is 2172659. The reversal of 2172645 is 5462712.

2172645 is a `hidden beast` number, since 2 + 17 + 2 + 645 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 859329 + 1313316 = 927^2 + 1146^2 .

It is not a de Polignac number, because 2172645 - 2² = 2172641 is a prime.

It is a d-powerful number, because it can be written as 2¹¹ + 1 + 7 + 2²¹ + 6⁵ + 4⁸ + 5³ .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2172641) 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, 24096 + ... + 24185.

It is an arithmetic number, because the mean of its divisors is an integer number (313833).

2^2172645 is an apocalyptic number.

It is an amenable number.

2172645 is a deficient number, since it is larger than the sum of its proper divisors (1593351).

2172645 is a wasteful number, since it uses less digits than its factorization.

2172645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48292 (or 48289 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The square root of 2172645 is about 1473.9894843587. The cubic root of 2172645 is about 129.5178391568.

The spelling of 2172645 in words is "two million, one hundred seventy-two thousand, six hundred forty-five".