309447 has 16 divisors (see below), whose sum is σ = 467680. Its totient is φ = 202176.

The previous prime is 309437. The next prime is 309457. The reversal of 309447 is 744903.

It is an interprime number because it is at equal distance from previous prime (309437) and next prime (309457).

It is not a de Polignac number, because 309447 - 2¹⁰ = 308423 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 309447.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 309447.

It is not an unprimeable number, because it can be changed into a prime (309437) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1893 + ... + 2049.

It is an arithmetic number, because the mean of its divisors is an integer number (29230).

2³⁰⁹⁴⁴⁷ is an apocalyptic number.

309447 is a deficient number, since it is larger than the sum of its proper divisors (158233).

309447 is a wasteful number, since it uses less digits than its factorization.

309447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239 (or 233 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 309447 is about 556.2796059537. The cubic root of 309447 is about 67.6387270364.

The spelling of 309447 in words is "three hundred nine thousand, four hundred forty-seven".