309669138 has 12 divisors (see below), whose sum is σ = 670949838. Its totient is φ = 103223040.

The previous prime is 309669133. The next prime is 309669167. The reversal of 309669138 is 831966903.

It can be written as a sum of positive squares in only one way, i.e., 190357209 + 119311929 = 13797^2 + 10923^2 .

It is a junction number, because it is equal to n+sod(n) for n = 309669093 and 309669102.

It is not an unprimeable number, because it can be changed into a prime (309669133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8601903 + ... + 8601938.

Almost surely, 2^309669138 is an apocalyptic number.

309669138 is an abundant number, since it is smaller than the sum of its proper divisors (361280700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

309669138 is a wasteful number, since it uses less digits than its factorization.

309669138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17203849 (or 17203846 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 45.

The square root of 309669138 is about 17597.4185038602. The cubic root of 309669138 is about 676.5490809240.

It can be divided in two parts, 30966 and 9138, that added together give a palindrome (40104).

The spelling of 309669138 in words is "three hundred nine million, six hundred sixty-nine thousand, one hundred thirty-eight".