2115509 has 4 divisors (see below), whose sum is σ = 2307840. Its totient is φ = 1923180.

The previous prime is 2115499. The next prime is 2115511. The reversal of 2115509 is 9055112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2115509 - 2⁴ = 2115493 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 (2115539) 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, 96149 + ... + 96170.

It is an arithmetic number, because the mean of its divisors is an integer number (576960).

2^2115509 is an apocalyptic number.

It is an amenable number.

2115509 is a deficient number, since it is larger than the sum of its proper divisors (192331).

2115509 is a wasteful number, since it uses less digits than its factorization.

2115509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192330.

The product of its (nonzero) digits is 450, while the sum is 23.

The square root of 2115509 is about 1454.4789445021. The cubic root of 2115509 is about 128.3723896793.

It can be divided in two parts, 2 and 115509, that added together give a palindrome (115511).

The spelling of 2115509 in words is "two million, one hundred fifteen thousand, five hundred nine".