2191749 has 8 divisors (see below), whose sum is σ = 3339840. Its totient is φ = 1252416.

The previous prime is 2191727. The next prime is 2191799. The reversal of 2191749 is 9471912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2191749 - 2⁸ = 2191493 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

2191749 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2191799) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52164 + ... + 52205.

It is an arithmetic number, because the mean of its divisors is an integer number (417480).

2^2191749 is an apocalyptic number.

It is an amenable number.

2191749 is a deficient number, since it is larger than the sum of its proper divisors (1148091).

2191749 is a wasteful number, since it uses less digits than its factorization.

2191749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104379.

The product of its digits is 4536, while the sum is 33.

The square root of 2191749 is about 1480.4556730953. The cubic root of 2191749 is about 129.8963473571.

The spelling of 2191749 in words is "two million, one hundred ninety-one thousand, seven hundred forty-nine".