2028309 has 4 divisors (see below), whose sum is σ = 2704416. Its totient is φ = 1352204.

The previous prime is 2028293. The next prime is 2028319. The reversal of 2028309 is 9038202.

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 2028309 - 2⁴ = 2028293 is a prime.

It is a super-2 number, since 2×2028309² = 8228074798962, which contains 22 as substring.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2028319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 338049 + ... + 338054.

It is an arithmetic number, because the mean of its divisors is an integer number (676104).

2^2028309 is an apocalyptic number.

It is an amenable number.

2028309 is a deficient number, since it is larger than the sum of its proper divisors (676107).

2028309 is an equidigital number, since it uses as much as digits as its factorization.

2028309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 676106.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 2028309 is about 1424.1871365800. The cubic root of 2028309 is about 126.5837738663.

The spelling of 2028309 in words is "two million, twenty-eight thousand, three hundred nine".