138921232681 has 24 divisors (see below), whose sum is σ = 174539879360. Its totient is φ = 108233405280.

The previous prime is 138921232661. The next prime is 138921232741. The reversal of 138921232681 is 186232129831.

It is not a de Polignac number, because 138921232681 - 2¹³ = 138921224489 is a prime.

It is a super-2 number, since 2×138921232681² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138921232601) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10697050 + ... + 10710028.

Almost surely, 2^138921232681 is an apocalyptic number.

138921232681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

138921232681 is a deficient number, since it is larger than the sum of its proper divisors (35618646679).

138921232681 is a wasteful number, since it uses less digits than its factorization.

138921232681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25645 (or 25634 counting only the distinct ones).

The product of its digits is 248832, while the sum is 46.

The spelling of 138921232681 in words is "one hundred thirty-eight billion, nine hundred twenty-one million, two hundred thirty-two thousand, six hundred eighty-one".