306139509 has 12 divisors (see below), whose sum is σ = 476217196. Its totient is φ = 188393472.

The previous prime is 306139459. The next prime is 306139511. The reversal of 306139509 is 905931603.

306139509 is a `hidden beast` number, since 30 + 613 + 9 + 5 + 0 + 9 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 74338884 + 231800625 = 8622^2 + 15225^2 .

It is not a de Polignac number, because 306139509 - 2⁹ = 306138997 is a prime.

It is a super-2 number, since 2×306139509² = 187442797941522162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (306139409) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1308172 + ... + 1308405.

Almost surely, 2^306139509 is an apocalyptic number.

306139509 is a gapful number since it is divisible by the number (39) formed by its first and last digit.

It is an amenable number.

306139509 is a deficient number, since it is larger than the sum of its proper divisors (170077687).

306139509 is a wasteful number, since it uses less digits than its factorization.

306139509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2616596 (or 2616593 counting only the distinct ones).

The product of its (nonzero) digits is 21870, while the sum is 36.

The square root of 306139509 is about 17496.8428294936. The cubic root of 306139509 is about 673.9688023962.

The spelling of 306139509 in words is "three hundred six million, one hundred thirty-nine thousand, five hundred nine".