309055220 has 18 divisors (see below), whose sum is σ = 649181106. Its totient is φ = 123590640.

The previous prime is 309055211. The next prime is 309055237. The reversal of 309055220 is 22550903.

It can be written as a sum of positive squares in only one way, i.e., 247244176 + 61811044 = 15724^2 + 7862^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 309055220.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 76655 + ... + 80585.

It is an arithmetic number, because the mean of its divisors is an integer number (36065617).

Almost surely, 2^309055220 is an apocalyptic number.

It is an amenable number.

309055220 is an abundant number, since it is smaller than the sum of its proper divisors (340125886).

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

309055220 is an frugal number, since it uses more digits than its factorization.

309055220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7871 (or 3938 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 26.

The square root of 309055220 is about 17579.9664391033. The cubic root of 309055220 is about 676.1016997418.

The spelling of 309055220 in words is "three hundred nine million, fifty-five thousand, two hundred twenty".