2091911 has 4 divisors (see below), whose sum is σ = 2159424. Its totient is φ = 2024400.

The previous prime is 2091889. The next prime is 2091913. The reversal of 2091911 is 1191902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1191902 = 2 ⋅595951.

It is a cyclic number.

It is not a de Polignac number, because 2091911 - 2⁶ = 2091847 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 (2091913) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33710 + ... + 33771.

It is an arithmetic number, because the mean of its divisors is an integer number (539856).

2^2091911 is an apocalyptic number.

2091911 is a deficient number, since it is larger than the sum of its proper divisors (67513).

2091911 is an equidigital number, since it uses as much as digits as its factorization.

2091911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67512.

The product of its (nonzero) digits is 162, while the sum is 23.

The square root of 2091911 is about 1446.3440116376. The cubic root of 2091911 is about 127.8932826333.

Subtracting from 2091911 its reverse (1191902), we obtain a palindrome (900009).

The spelling of 2091911 in words is "two million, ninety-one thousand, nine hundred eleven".