2158609 has 16 divisors (see below), whose sum is σ = 2479680. Its totient is φ = 1866240.

The previous prime is 2158603. The next prime is 2158621. The reversal of 2158609 is 9068512.

It is a cyclic number.

It is not a de Polignac number, because 2158609 - 2³ = 2158601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2158601) 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 15 ways as a sum of consecutive naturals, for example, 13162 + ... + 13324.

It is an arithmetic number, because the mean of its divisors is an integer number (154980).

2^2158609 is an apocalyptic number.

It is an amenable number.

2158609 is a deficient number, since it is larger than the sum of its proper divisors (321071).

2158609 is a wasteful number, since it uses less digits than its factorization.

2158609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 2158609 is about 1469.2205416478. The cubic root of 2158609 is about 129.2383271224.

Subtracting 2158609 from its reverse (9068512), we obtain a triangular number (6909903 = T₃₇₁₇).

The spelling of 2158609 in words is "two million, one hundred fifty-eight thousand, six hundred nine".