2155909 has 8 divisors (see below), whose sum is σ = 2498240. Its totient is φ = 1822176.

The previous prime is 2155883. The next prime is 2155931. The reversal of 2155909 is 9095512.

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 2155909 - 2⁵ = 2155877 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 (2155999) 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, 1599 + ... + 2620.

It is an arithmetic number, because the mean of its divisors is an integer number (312280).

2^2155909 is an apocalyptic number.

It is an amenable number.

2155909 is a deficient number, since it is larger than the sum of its proper divisors (342331).

2155909 is an equidigital number, since it uses as much as digits as its factorization.

2155909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4299.

The product of its (nonzero) digits is 4050, while the sum is 31.

The square root of 2155909 is about 1468.3013995771. The cubic root of 2155909 is about 129.1844206374.

The spelling of 2155909 in words is "two million, one hundred fifty-five thousand, nine hundred nine".