309808 has 30 divisors (see below), whose sum is σ = 647156. Its totient is φ = 143616.

The previous prime is 309797. The next prime is 309811. The reversal of 309808 is 808903.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4591 + ... + 4657.

2³⁰⁹⁸⁰⁸ 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 309808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (323578).

309808 is an abundant number, since it is smaller than the sum of its proper divisors (337348).

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

309808 is a wasteful number, since it uses less digits than its factorization.

309808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109 (or 86 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 309808 is about 556.6039884873. The cubic root of 309808 is about 67.6650191979.

The spelling of 309808 in words is "three hundred nine thousand, eight hundred eight".