309679 has 4 divisors (see below), whose sum is σ = 315576. Its totient is φ = 303784.

The previous prime is 309677. The next prime is 309707. The reversal of 309679 is 976903.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 976903 = 31 ⋅31513.

It is a cyclic number.

It is not a de Polignac number, because 309679 - 2¹ = 309677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (309671) 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, 2869 + ... + 2974.

It is an arithmetic number, because the mean of its divisors is an integer number (78894).

2³⁰⁹⁶⁷⁹ is an apocalyptic number.

309679 is a deficient number, since it is larger than the sum of its proper divisors (5897).

309679 is an equidigital number, since it uses as much as digits as its factorization.

309679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5896.

The product of its (nonzero) digits is 10206, while the sum is 34.

The square root of 309679 is about 556.4880951108. The cubic root of 309679 is about 67.6556262843.

It can be divided in two parts, 30967 and 9, that added together give a square (30976 = 176²).

The spelling of 309679 in words is "three hundred nine thousand, six hundred seventy-nine".