138527009 has 4 divisors (see below), whose sum is σ = 138589716. Its totient is φ = 138464304.

The previous prime is 138526991. The next prime is 138527021. The reversal of 138527009 is 900725831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 900725831 = 53 ⋅16994827.

It can be written as a sum of positive squares in 2 ways, for example, as 84180625 + 54346384 = 9175^2 + 7372^2 .

It is a cyclic number.

It is not a de Polignac number, because 138527009 - 2¹⁶ = 138461473 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138527009.

It is not an unprimeable number, because it can be changed into a prime (138527089) 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, 27914 + ... + 32499.

It is an arithmetic number, because the mean of its divisors is an integer number (34647429).

Almost surely, 2^138527009 is an apocalyptic number.

It is an amenable number.

138527009 is a deficient number, since it is larger than the sum of its proper divisors (62707).

138527009 is an equidigital number, since it uses as much as digits as its factorization.

138527009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62706.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 138527009 is about 11769.7497424542. The cubic root of 138527009 is about 517.4219151401.

The spelling of 138527009 in words is "one hundred thirty-eight million, five hundred twenty-seven thousand, nine".