309923 has 4 divisors (see below), whose sum is σ = 320640. Its totient is φ = 299208.

The previous prime is 309899. The next prime is 309929. The reversal of 309923 is 329903.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 329903 = 7 ⋅47129.

It is a cyclic number.

It is not a de Polignac number, because 309923 - 2⁸ = 309667 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 309892 and 309901.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 309923.

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 3 ways as a sum of consecutive naturals, for example, 5315 + ... + 5372.

It is an arithmetic number, because the mean of its divisors is an integer number (80160).

2³⁰⁹⁹²³ is an apocalyptic number.

309923 is a deficient number, since it is larger than the sum of its proper divisors (10717).

309923 is a wasteful number, since it uses less digits than its factorization.

309923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10716.

The product of its (nonzero) digits is 1458, while the sum is 26.

The square root of 309923 is about 556.7072839473. The cubic root of 309923 is about 67.6733905274.

The spelling of 309923 in words is "three hundred nine thousand, nine hundred twenty-three".