309379905 has 20 divisors (see below), whose sum is σ = 554592852. Its totient is φ = 165002400.

The previous prime is 309379843. The next prime is 309379933. The reversal of 309379905 is 509973903.

It can be written as a sum of positive squares in 2 ways, for example, as 246081969 + 63297936 = 15687^2 + 7956^2 .

It is not a de Polignac number, because 309379905 - 2⁹ = 309379393 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

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 in 19 ways as a sum of consecutive naturals, for example, 381546 + ... + 382355.

Almost surely, 2^309379905 is an apocalyptic number.

It is an amenable number.

309379905 is a deficient number, since it is larger than the sum of its proper divisors (245212947).

309379905 is an equidigital number, since it uses as much as digits as its factorization.

309379905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 763918 (or 763909 counting only the distinct ones).

The product of its (nonzero) digits is 229635, while the sum is 45.

The square root of 309379905 is about 17589.1985320537. The cubic root of 309379905 is about 676.3383815569.

The spelling of 309379905 in words is "three hundred nine million, three hundred seventy-nine thousand, nine hundred five".