2109581 has 8 divisors (see below), whose sum is σ = 2306304. Its totient is φ = 1920960.

The previous prime is 2109577. The next prime is 2109593. The reversal of 2109581 is 1859012.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 2109581 - 2² = 2109577 is a prime.

It is a super-2 number, since 2×2109581² = 8900663991122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2109581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2109521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1475 + ... + 2528.

It is an arithmetic number, because the mean of its divisors is an integer number (288288).

2^2109581 is an apocalyptic number.

It is an amenable number.

2109581 is a deficient number, since it is larger than the sum of its proper divisors (196723).

2109581 is a wasteful number, since it uses less digits than its factorization.

2109581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4051.

The product of its (nonzero) digits is 720, while the sum is 26.

The square root of 2109581 is about 1452.4396717248. The cubic root of 2109581 is about 128.2523707395.

The spelling of 2109581 in words is "two million, one hundred nine thousand, five hundred eighty-one".