1646009 has 4 divisors (see below), whose sum is σ = 1661220. Its totient is φ = 1630800.

The previous prime is 1645999. The next prime is 1646017. The reversal of 1646009 is 9006461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9006461 = 31 ⋅290531.

It can be written as a sum of positive squares in 2 ways, for example, as 640000 + 1006009 = 800^2 + 1003^2 .

It is a cyclic number.

It is not a de Polignac number, because 1646009 - 2²⁰ = 597433 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1646209) 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, 7442 + ... + 7659.

It is an arithmetic number, because the mean of its divisors is an integer number (415305).

2^1646009 is an apocalyptic number.

It is an amenable number.

1646009 is a deficient number, since it is larger than the sum of its proper divisors (15211).

1646009 is a wasteful number, since it uses less digits than its factorization.

1646009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15210.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 1646009 is about 1282.9688226921. The cubic root of 1646009 is about 118.0712248349.

The spelling of 1646009 in words is "one million, six hundred forty-six thousand, nine".