309940 has 12 divisors (see below), whose sum is σ = 650916. Its totient is φ = 123968.

The previous prime is 309937. The next prime is 309977. The reversal of 309940 is 49903.

309940 is nontrivially palindromic in base 16.

309940 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 224676 + 85264 = 474^2 + 292^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7729 + ... + 7768.

It is an arithmetic number, because the mean of its divisors is an integer number (54243).

2³⁰⁹⁹⁴⁰ is an apocalyptic number.

It is an amenable number.

309940 is an abundant number, since it is smaller than the sum of its proper divisors (340976).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

309940 is a wasteful number, since it uses less digits than its factorization.

309940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15506 (or 15504 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 309940 is about 556.7225520850. The cubic root of 309940 is about 67.6746278526.

The spelling of 309940 in words is "three hundred nine thousand, nine hundred forty".