138520837 has 32 divisors (see below), whose sum is σ = 176569344. Its totient is φ = 105753600.

The previous prime is 138520831. The next prime is 138520861. The reversal of 138520837 is 738025831.

It is a cyclic number.

It is not a de Polignac number, because 138520837 - 2³ = 138520829 is a prime.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 138520796 and 138520805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138520831) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 511012 + ... + 511282.

It is an arithmetic number, because the mean of its divisors is an integer number (5517792).

Almost surely, 2^138520837 is an apocalyptic number.

It is an amenable number.

138520837 is a deficient number, since it is larger than the sum of its proper divisors (38048507).

138520837 is a wasteful number, since it uses less digits than its factorization.

138520837 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 469.

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 138520837 is about 11769.4875419451. The cubic root of 138520837 is about 517.4142305365.

It can be divided in two parts, 1385 and 20837, that added together give a palindrome (22222).

The spelling of 138520837 in words is "one hundred thirty-eight million, five hundred twenty thousand, eight hundred thirty-seven".