309132820 has 12 divisors (see below), whose sum is σ = 649178964. Its totient is φ = 123653120.

The previous prime is 309132809. The next prime is 309132823. The reversal of 309132820 is 28231903.

It can be written as a sum of positive squares in 2 ways, for example, as 238270096 + 70862724 = 15436^2 + 8418^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (309132823) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7728301 + ... + 7728340.

It is an arithmetic number, because the mean of its divisors is an integer number (54098247).

Almost surely, 2^309132820 is an apocalyptic number.

It is an amenable number.

309132820 is an abundant number, since it is smaller than the sum of its proper divisors (340046144).

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

309132820 is a wasteful number, since it uses less digits than its factorization.

309132820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15456650 (or 15456648 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 309132820 is about 17582.1733582626. The cubic root of 309132820 is about 676.1582819726.

It can be divided in two parts, 30913 and 2820, that added together give a palindrome (33733).

The spelling of 309132820 in words is "three hundred nine million, one hundred thirty-two thousand, eight hundred twenty".