2100309 has 4 divisors (see below), whose sum is σ = 2800416. Its totient is φ = 1400204.

The previous prime is 2100277. The next prime is 2100313. The reversal of 2100309 is 9030012.

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 2100309 - 2⁵ = 2100277 is a prime.

It is a super-2 number, since 2×2100309² = 8822595790962, 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 (2100409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 350049 + ... + 350054.

It is an arithmetic number, because the mean of its divisors is an integer number (700104).

2^2100309 is an apocalyptic number.

It is an amenable number.

2100309 is a deficient number, since it is larger than the sum of its proper divisors (700107).

2100309 is an equidigital number, since it uses as much as digits as its factorization.

2100309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 700106.

The product of its (nonzero) digits is 54, while the sum is 15.

The square root of 2100309 is about 1449.2442858262. The cubic root of 2100309 is about 128.0641971266.

The spelling of 2100309 in words is "two million, one hundred thousand, three hundred nine".