309921923 has 2 divisors, whose sum is σ = 309921924. Its totient is φ = 309921922.

The previous prime is 309921893. The next prime is 309921961. The reversal of 309921923 is 329129903.

It is an a-pointer prime, because the next prime (309921961) can be obtained adding 309921923 to its sum of digits (38).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 309921923 - 2¹⁴ = 309905539 is a prime.

It is not a weakly prime, because it can be changed into another prime (309926923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154960961 + 154960962.

It is an arithmetic number, because the mean of its divisors is an integer number (154960962).

Almost surely, 2^309921923 is an apocalyptic number.

309921923 is a deficient number, since it is larger than the sum of its proper divisors (1).

309921923 is an equidigital number, since it uses as much as digits as its factorization.

309921923 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26244, while the sum is 38.

The square root of 309921923 is about 17604.5994842257. The cubic root of 309921923 is about 676.7331213769.

The spelling of 309921923 in words is "three hundred nine million, nine hundred twenty-one thousand, nine hundred twenty-three".