309039139 has 4 divisors (see below), whose sum is σ = 309081424. Its totient is φ = 308996856.

The previous prime is 309039119. The next prime is 309039163. The reversal of 309039139 is 931930903.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 931930903 = 499 ⋅1867597.

It is a cyclic number.

It is not a de Polignac number, because 309039139 - 2¹⁵ = 309006371 is a prime.

It is a super-4 number, since 4×309039139⁴ (a number of 35 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a deceptive number, since it divides R_309039138.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 309039098 and 309039107.

It is not an unprimeable number, because it can be changed into a prime (309039119) 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, 7047 + ... + 25840.

It is an arithmetic number, because the mean of its divisors is an integer number (77270356).

Almost surely, 2^309039139 is an apocalyptic number.

309039139 is the 9397-th nonagonal number.

309039139 is a deficient number, since it is larger than the sum of its proper divisors (42285).

309039139 is an equidigital number, since it uses as much as digits as its factorization.

309039139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42284.

The product of its (nonzero) digits is 19683, while the sum is 37.

The square root of 309039139 is about 17579.5090659552. The cubic root of 309039139 is about 676.0899730564.

The spelling of 309039139 in words is "three hundred nine million, thirty-nine thousand, one hundred thirty-nine".