309223128 has 32 divisors (see below), whose sum is σ = 773660160. Its totient is φ = 102994080.

The previous prime is 309223073. The next prime is 309223139. The reversal of 309223128 is 821322903.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 309223095 and 309223104.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32001 + ... + 40527.

It is an arithmetic number, because the mean of its divisors is an integer number (24176880).

Almost surely, 2^309223128 is an apocalyptic number.

It is an amenable number.

309223128 is an abundant number, since it is smaller than the sum of its proper divisors (464437032).

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

309223128 is a wasteful number, since it uses less digits than its factorization.

309223128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10047 (or 10043 counting only the distinct ones).

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

The square root of 309223128 is about 17584.7413401506. The cubic root of 309223128 is about 676.2241183521.

The spelling of 309223128 in words is "three hundred nine million, two hundred twenty-three thousand, one hundred twenty-eight".