309138 has 16 divisors (see below), whose sum is σ = 628320. Its totient is φ = 101376.

The previous prime is 309137. The next prime is 309157. The reversal of 309138 is 831903.

It is not an unprimeable number, because it can be changed into a prime (309131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18 + ... + 786.

It is an arithmetic number, because the mean of its divisors is an integer number (39270).

2³⁰⁹¹³⁸ is an apocalyptic number.

309138 is an abundant number, since it is smaller than the sum of its proper divisors (319182).

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

309138 is a wasteful number, since it uses less digits than its factorization.

309138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 841.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 309138 is about 556.0017985582. The cubic root of 309138 is about 67.6162058645.

The spelling of 309138 in words is "three hundred nine thousand, one hundred thirty-eight".