2172661 has 4 divisors (see below), whose sum is σ = 2223232. Its totient is φ = 2122092.

The previous prime is 2172659. The next prime is 2172673. The reversal of 2172661 is 1662712.

2172661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2172661 - 2¹ = 2172659 is a prime.

It is a Duffinian number.

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 pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25221 + ... + 25306.

It is an arithmetic number, because the mean of its divisors is an integer number (555808).

2^2172661 is an apocalyptic number.

It is an amenable number.

2172661 is a deficient number, since it is larger than the sum of its proper divisors (50571).

2172661 is an equidigital number, since it uses as much as digits as its factorization.

2172661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50570.

The product of its digits is 1008, while the sum is 25.

The square root of 2172661 is about 1473.9949117958. The cubic root of 2172661 is about 129.5181570919.

The spelling of 2172661 in words is "two million, one hundred seventy-two thousand, six hundred sixty-one".