2171009 has 4 divisors (see below), whose sum is σ = 2176980. Its totient is φ = 2165040.

The previous prime is 2171003. The next prime is 2171011. The reversal of 2171009 is 9001712.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 595984 + 1575025 = 772^2 + 1255^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2171009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2171003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2402 + ... + 3179.

It is an arithmetic number, because the mean of its divisors is an integer number (544245).

2^2171009 is an apocalyptic number.

It is an amenable number.

2171009 is a deficient number, since it is larger than the sum of its proper divisors (5971).

2171009 is an equidigital number, since it uses as much as digits as its factorization.

2171009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5970.

The product of its (nonzero) digits is 126, while the sum is 20.

The square root of 2171009 is about 1473.4344233796. The cubic root of 2171009 is about 129.4853220495.

The spelling of 2171009 in words is "two million, one hundred seventy-one thousand, nine".