309929 has 2 divisors, whose sum is σ = 309930. Its totient is φ = 309928.

The previous prime is 309899. The next prime is 309931. The reversal of 309929 is 929903.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 204304 + 105625 = 452^2 + 325^2 .

It is a cyclic number.

It is not a de Polignac number, because 309929 - 2¹⁶ = 244393 is a prime.

Together with 309931, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 309895 and 309904.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 309929.

It is not a weakly prime, because it can be changed into another prime (309989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154964 + 154965.

It is an arithmetic number, because the mean of its divisors is an integer number (154965).

2³⁰⁹⁹²⁹ is an apocalyptic number.

It is an amenable number.

309929 is a deficient number, since it is larger than the sum of its proper divisors (1).

309929 is an equidigital number, since it uses as much as digits as its factorization.

309929 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4374, while the sum is 32.

The square root of 309929 is about 556.7126727496. The cubic root of 309929 is about 67.6738272356.

The spelling of 309929 in words is "three hundred nine thousand, nine hundred twenty-nine".