138386521 has 32 divisors (see below), whose sum is σ = 180633600. Its totient is φ = 103057920.

The previous prime is 138386483. The next prime is 138386531. The reversal of 138386521 is 125683831.

It is not a de Polignac number, because 138386521 - 2¹¹ = 138384473 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138386531) 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, 107560 + ... + 108838.

It is an arithmetic number, because the mean of its divisors is an integer number (5644800).

Almost surely, 2^138386521 is an apocalyptic number.

It is an amenable number.

138386521 is a deficient number, since it is larger than the sum of its proper divisors (42247079).

138386521 is a wasteful number, since it uses less digits than its factorization.

138386521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1369.

The product of its digits is 34560, while the sum is 37.

The square root of 138386521 is about 11763.7800472467. The cubic root of 138386521 is about 517.2469404597.

The spelling of 138386521 in words is "one hundred thirty-eight million, three hundred eighty-six thousand, five hundred twenty-one".