138681991512 has 64 divisors (see below), whose sum is σ = 389983701600. Its totient is φ = 46227324672.

The previous prime is 138681991489. The next prime is 138681991517. The reversal of 138681991512 is 215199186831.

It is a happy number.

138681991512 is a `hidden beast` number, since 1 + 38 + 6 + 8 + 1 + 9 + 91 + 512 = 666.

138681991512 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×138681991512² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138681991517) 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, 3945753 + ... + 3980744.

Almost surely, 2^138681991512 is an apocalyptic number.

138681991512 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

138681991512 is an abundant number, since it is smaller than the sum of its proper divisors (251301710088).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138681991512 is an frugal number, since it uses more digits than its factorization.

138681991512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7926524 (or 7926502 counting only the distinct ones).

The product of its digits is 933120, while the sum is 54.

The spelling of 138681991512 in words is "one hundred thirty-eight billion, six hundred eighty-one million, nine hundred ninety-one thousand, five hundred twelve".