2309681 has 4 divisors (see below), whose sum is σ = 2519664. Its totient is φ = 2099700.

The previous prime is 2309677. The next prime is 2309689. The reversal of 2309681 is 1869032.

2309681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 2309681 - 2² = 2309677 is a prime.

It is a super-2 number, since 2×2309681² = 10669252643522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2309689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104975 + ... + 104996.

It is an arithmetic number, because the mean of its divisors is an integer number (629916).

2^2309681 is an apocalyptic number.

It is an amenable number.

2309681 is a deficient number, since it is larger than the sum of its proper divisors (209983).

2309681 is a wasteful number, since it uses less digits than its factorization.

2309681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209982.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 2309681 is about 1519.7634684384. The cubic root of 2309681 is about 132.1855555363.

The spelling of 2309681 in words is "two million, three hundred nine thousand, six hundred eighty-one".