2171609 has 4 divisors (see below), whose sum is σ = 2369040. Its totient is φ = 1974180.

The previous prime is 2171599. The next prime is 2171621. The reversal of 2171609 is 9061712.

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 2171609 - 2⁴ = 2171593 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (2171639) 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, 98699 + ... + 98720.

It is an arithmetic number, because the mean of its divisors is an integer number (592260).

2^2171609 is an apocalyptic number.

It is an amenable number.

2171609 is a deficient number, since it is larger than the sum of its proper divisors (197431).

2171609 is a wasteful number, since it uses less digits than its factorization.

2171609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197430.

The product of its (nonzero) digits is 756, while the sum is 26.

The square root of 2171609 is about 1473.6380152534. The cubic root of 2171609 is about 129.4972495354.

The spelling of 2171609 in words is "two million, one hundred seventy-one thousand, six hundred nine".