2125309 has 4 divisors (see below), whose sum is σ = 2139004. Its totient is φ = 2111616.

The previous prime is 2125273. The next prime is 2125313. The reversal of 2125309 is 9035212.

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 1493284 + 632025 = 1222^2 + 795^2 .

It is a cyclic number.

It is not a de Polignac number, because 2125309 - 2⁷ = 2125181 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2125309.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2125339) 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, 6612 + ... + 6925.

It is an arithmetic number, because the mean of its divisors is an integer number (534751).

2^2125309 is an apocalyptic number.

It is an amenable number.

2125309 is a deficient number, since it is larger than the sum of its proper divisors (13695).

2125309 is a wasteful number, since it uses less digits than its factorization.

2125309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13694.

The product of its (nonzero) digits is 540, while the sum is 22.

The square root of 2125309 is about 1457.8439559843. The cubic root of 2125309 is about 128.5703108074.

Subtracting 2125309 from its reverse (9035212), we obtain a triangular number (6909903 = T₃₇₁₇).

The spelling of 2125309 in words is "two million, one hundred twenty-five thousand, three hundred nine".