309381240 has 192 divisors, whose sum is σ = 1105090560. Its totient is φ = 67806720.

The previous prime is 309381239. The next prime is 309381253. The reversal of 309381240 is 42183903.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 309381198 and 309381207.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2838306 + ... + 2838414.

It is an arithmetic number, because the mean of its divisors is an integer number (5755680).

Almost surely, 2^309381240 is an apocalyptic number.

309381240 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 309381240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (552545280).

309381240 is an abundant number, since it is smaller than the sum of its proper divisors (795709320).

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

309381240 is a wasteful number, since it uses less digits than its factorization.

309381240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270 (or 157 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 309381240 is about 17589.2364814394. The cubic root of 309381240 is about 676.3393543743.

The spelling of 309381240 in words is "three hundred nine million, three hundred eighty-one thousand, two hundred forty".