138645216 has 96 divisors (see below), whose sum is σ = 415406880. Its totient is φ = 44955648.

The previous prime is 138645211. The next prime is 138645239. The reversal of 138645216 is 612546831.

It is a happy number.

138645216 is a `hidden beast` number, since 1 + 3 + 8 + 645 + 2 + 1 + 6 = 666.

138645216 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 (96).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138645211) 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 15 ways as a sum of consecutive naturals, for example, 29800 + ... + 34136.

It is an arithmetic number, because the mean of its divisors is an integer number (4327155).

Almost surely, 2^138645216 is an apocalyptic number.

138645216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138645216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (207703440).

138645216 is an abundant number, since it is smaller than the sum of its proper divisors (276761664).

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

138645216 is a wasteful number, since it uses less digits than its factorization.

138645216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4393 (or 4379 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 138645216 is about 11774.7703162312. The cubic root of 138645216 is about 517.5690477077.

The spelling of 138645216 in words is "one hundred thirty-eight million, six hundred forty-five thousand, two hundred sixteen".