138127209 has 8 divisors (see below), whose sum is σ = 200912352. Its totient is φ = 83713440.

The previous prime is 138127183. The next prime is 138127211. The reversal of 138127209 is 902721831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 138127209 - 2⁷ = 138127081 is a prime.

It is a super-2 number, since 2×138127209² = 38158251732259362, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 4185673 = 138127209 / (1 + 3 + 8 + 1 + 2 + 7 + 2 + 0 + 9).

It is a self number, because there is not a number n which added to its sum of digits gives 138127209.

It is not an unprimeable number, because it can be changed into a prime (138127279) 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, 2092804 + ... + 2092869.

It is an arithmetic number, because the mean of its divisors is an integer number (25114044).

Almost surely, 2^138127209 is an apocalyptic number.

It is an amenable number.

138127209 is a deficient number, since it is larger than the sum of its proper divisors (62785143).

138127209 is a wasteful number, since it uses less digits than its factorization.

138127209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4185687.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 138127209 is about 11752.7532518980. The cubic root of 138127209 is about 516.9236618566.

The spelling of 138127209 in words is "one hundred thirty-eight million, one hundred twenty-seven thousand, two hundred nine".