309966 has 16 divisors (see below), whose sum is σ = 652800. Its totient is φ = 97848.

The previous prime is 309937. The next prime is 309977. The reversal of 309966 is 669903.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1246 + ... + 1473.

It is an arithmetic number, because the mean of its divisors is an integer number (40800).

2³⁰⁹⁹⁶⁶ is an apocalyptic number.

309966 is an abundant number, since it is smaller than the sum of its proper divisors (342834).

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

309966 is a wasteful number, since it uses less digits than its factorization.

309966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2743.

The product of its (nonzero) digits is 8748, while the sum is 33.

The square root of 309966 is about 556.7459025444. The cubic root of 309966 is about 67.6765201448.

It can be divided in two parts, 309 and 966, that added together give a triangular number (1275 = T₅₀).

The spelling of 309966 in words is "three hundred nine thousand, nine hundred sixty-six".