1648209 has 4 divisors (see below), whose sum is σ = 2197616. Its totient is φ = 1098804.

The previous prime is 1648187. The next prime is 1648217. The reversal of 1648209 is 9028461.

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 not a de Polignac number, because 1648209 - 2⁷ = 1648081 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1648259) 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, 274699 + ... + 274704.

It is an arithmetic number, because the mean of its divisors is an integer number (549404).

2^1648209 is an apocalyptic number.

It is an amenable number.

1648209 is a deficient number, since it is larger than the sum of its proper divisors (549407).

1648209 is an equidigital number, since it uses as much as digits as its factorization.

1648209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 549406.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 1648209 is about 1283.8259227793. The cubic root of 1648209 is about 118.1238047526.

The spelling of 1648209 in words is "one million, six hundred forty-eight thousand, two hundred nine".