309873 has 4 divisors (see below), whose sum is σ = 413168. Its totient is φ = 206580.

The previous prime is 309857. The next prime is 309877. The reversal of 309873 is 378903.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 309873 - 2⁴ = 309857 is a prime.

It is a super-2 number, since 2×309873² = 192042552258, which contains 22 as substring.

It is a D-number.

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 309873.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 309873.

It is not an unprimeable number, because it can be changed into a prime (309877) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51643 + ... + 51648.

It is an arithmetic number, because the mean of its divisors is an integer number (103292).

2³⁰⁹⁸⁷³ is an apocalyptic number.

It is an amenable number.

309873 is a deficient number, since it is larger than the sum of its proper divisors (103295).

309873 is a wasteful number, since it uses less digits than its factorization.

309873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103294.

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 309873 is about 556.6623752330. The cubic root of 309873 is about 67.6697510734.

Adding to 309873 its sum of digits (30), we get a palindrome (309903).

The spelling of 309873 in words is "three hundred nine thousand, eight hundred seventy-three".