309969 has 24 divisors (see below), whose sum is σ = 509184. Its totient is φ = 180000.

The previous prime is 309937. The next prime is 309977. The reversal of 309969 is 969903.

It is not a de Polignac number, because 309969 - 2⁵ = 309937 is a prime.

It is a super-2 number, since 2×309969² = 192161561922, which contains 22 as substring.

309969 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (309929) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3019 + ... + 3119.

It is an arithmetic number, because the mean of its divisors is an integer number (21216).

2³⁰⁹⁹⁶⁹ is an apocalyptic number.

It is an amenable number.

309969 is a deficient number, since it is larger than the sum of its proper divisors (199215).

309969 is a wasteful number, since it uses less digits than its factorization.

309969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 146 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 36.

The square root of 309969 is about 556.7485967652. The cubic root of 309969 is about 67.6767384794.

It can be divided in two parts, 30 and 9969, that added together give a palindrome (9999).

The spelling of 309969 in words is "three hundred nine thousand, nine hundred sixty-nine".