309242920 has 96 divisors (see below), whose sum is σ = 857099880. Its totient is φ = 99778560.

The previous prime is 309242909. The next prime is 309242933. The reversal of 309242920 is 29242903.

It can be written as a sum of positive squares in 4 ways, for example, as 306740196 + 2502724 = 17514^2 + 1582^2 .

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 28680 + ... + 37960.

Almost surely, 2^309242920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 309242920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (428549940).

309242920 is an abundant number, since it is smaller than the sum of its proper divisors (547856960).

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

309242920 is a wasteful number, since it uses less digits than its factorization.

309242920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9323 (or 9312 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 309242920 is about 17585.3040917694. The cubic root of 309242920 is about 676.2385454125.

The spelling of 309242920 in words is "three hundred nine million, two hundred forty-two thousand, nine hundred twenty".