309121240 has 16 divisors (see below), whose sum is σ = 695522880. Its totient is φ = 123648480.

The previous prime is 309121223. The next prime is 309121247. The reversal of 309121240 is 42121903.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (309121247) 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, 3863976 + ... + 3864055.

It is an arithmetic number, because the mean of its divisors is an integer number (43470180).

Almost surely, 2^309121240 is an apocalyptic number.

It is an amenable number.

309121240 is an abundant number, since it is smaller than the sum of its proper divisors (386401640).

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

309121240 is a wasteful number, since it uses less digits than its factorization.

309121240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7728042 (or 7728038 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 309121240 is about 17581.8440443544. The cubic root of 309121240 is about 676.1498389883.

The spelling of 309121240 in words is "three hundred nine million, one hundred twenty-one thousand, two hundred forty".