2109591 has 16 divisors (see below), whose sum is σ = 3409920. Its totient is φ = 1278360.

The previous prime is 2109577. The next prime is 2109593. The reversal of 2109591 is 1959012.

It is a happy number.

It is not a de Polignac number, because 2109591 - 2¹¹ = 2107543 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2109593) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3255 + ... + 3848.

It is an arithmetic number, because the mean of its divisors is an integer number (213120).

2^2109591 is an apocalyptic number.

2109591 is a deficient number, since it is larger than the sum of its proper divisors (1300329).

2109591 is a wasteful number, since it uses less digits than its factorization.

2109591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7123 (or 7117 counting only the distinct ones).

The product of its (nonzero) digits is 810, while the sum is 27.

The square root of 2109591 is about 1452.4431142045. The cubic root of 2109591 is about 128.2525733898.

It can be divided in two parts, 210 and 9591, that added together give a square (9801 = 99²).

The spelling of 2109591 in words is "two million, one hundred nine thousand, five hundred ninety-one".