138918356 has 24 divisors (see below), whose sum is σ = 260073576. Its totient is φ = 64696320.

The previous prime is 138918341. The next prime is 138918359. The reversal of 138918356 is 653819831.

138918356 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 80640400 + 58277956 = 8980^2 + 7634^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138918359) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3935 + ... + 17126.

It is an arithmetic number, because the mean of its divisors is an integer number (10836399).

Almost surely, 2^138918356 is an apocalyptic number.

It is an amenable number.

138918356 is a deficient number, since it is larger than the sum of its proper divisors (121155220).

138918356 is a wasteful number, since it uses less digits than its factorization.

138918356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21179 (or 21177 counting only the distinct ones).

The product of its digits is 155520, while the sum is 44.

The square root of 138918356 is about 11786.3631371174. The cubic root of 138918356 is about 517.9087062020.

The spelling of 138918356 in words is "one hundred thirty-eight million, nine hundred eighteen thousand, three hundred fifty-six".