309828240 has 200 divisors, whose sum is σ = 1087039800. Its totient is φ = 81782784.

The previous prime is 309828227. The next prime is 309828241. The reversal of 309828240 is 42828903.

It can be written as a sum of positive squares in 4 ways, for example, as 67963536 + 241864704 = 8244^2 + 15552^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 309828195 and 309828204.

It is not an unprimeable number, because it can be changed into a prime (309828241) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 887586 + ... + 887934.

It is an arithmetic number, because the mean of its divisors is an integer number (5435199).

Almost surely, 2^309828240 is an apocalyptic number.

309828240 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 309828240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (543519900).

309828240 is an abundant number, since it is smaller than the sum of its proper divisors (777211560).

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

309828240 is a wasteful number, since it uses less digits than its factorization.

309828240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511 (or 496 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 309828240 is about 17601.9385296052. The cubic root of 309828240 is about 676.6649270206.

The spelling of 309828240 in words is "three hundred nine million, eight hundred twenty-eight thousand, two hundred forty".