2191845 has 16 divisors (see below), whose sum is σ = 3582720. Its totient is φ = 1143744.

The previous prime is 2191823. The next prime is 2191873. The reversal of 2191845 is 5481912.

It is a happy number.

2191845 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2191845 - 2¹⁰ = 2190821 is a prime.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 850 + ... + 2259.

It is an arithmetic number, because the mean of its divisors is an integer number (223920).

2^2191845 is an apocalyptic number.

It is an amenable number.

2191845 is a deficient number, since it is larger than the sum of its proper divisors (1390875).

2191845 is a wasteful number, since it uses less digits than its factorization.

2191845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3164.

The product of its digits is 2880, while the sum is 30.

The square root of 2191845 is about 1480.4880951902. The cubic root of 2191845 is about 129.8982438436.

It can be divided in two parts, 21918 and 45, that multiplied together give a triangular number (986310 = T₁₄₀₄).

The spelling of 2191845 in words is "two million, one hundred ninety-one thousand, eight hundred forty-five".