138836621 has 16 divisors (see below), whose sum is σ = 173352960. Its totient is φ = 108023280.

The previous prime is 138836611. The next prime is 138836623. The reversal of 138836621 is 126638831.

It is a cyclic number.

It is not a de Polignac number, because 138836621 - 2⁶ = 138836557 is a prime.

It is a super-3 number, since 3×138836621³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138836623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 100880 + ... + 102246.

It is an arithmetic number, because the mean of its divisors is an integer number (10834560).

Almost surely, 2^138836621 is an apocalyptic number.

138836621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

138836621 is a deficient number, since it is larger than the sum of its proper divisors (34516339).

138836621 is a wasteful number, since it uses less digits than its factorization.

138836621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2704.

The product of its digits is 41472, while the sum is 38.

The square root of 138836621 is about 11782.8952723853. The cubic root of 138836621 is about 517.8071127814.

The spelling of 138836621 in words is "one hundred thirty-eight million, eight hundred thirty-six thousand, six hundred twenty-one".