138978012 has 12 divisors (see below), whose sum is σ = 324282056. Its totient is φ = 46326000.

The previous prime is 138978001. The next prime is 138978017. The reversal of 138978012 is 210879831.

138978012 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138978017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5790739 + ... + 5790762.

Almost surely, 2^138978012 is an apocalyptic number.

138978012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

138978012 is an abundant number, since it is smaller than the sum of its proper divisors (185304044).

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

138978012 is a wasteful number, since it uses less digits than its factorization.

138978012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11581508 (or 11581506 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 39.

The square root of 138978012 is about 11788.8935867621. The cubic root of 138978012 is about 517.9828311319.

It can be divided in two parts, 1389 and 78012, that added together give a triangular number (79401 = T₃₉₈).

The spelling of 138978012 in words is "one hundred thirty-eight million, nine hundred seventy-eight thousand, twelve".