138917856 has 96 divisors (see below), whose sum is σ = 454664448. Its totient is φ = 36080640.

The previous prime is 138917773. The next prime is 138917893. The reversal of 138917856 is 658719831.

138917856 is digitally balanced in base 2, 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 (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2005 + ... + 16788.

It is an arithmetic number, because the mean of its divisors is an integer number (4736088).

Almost surely, 2^138917856 is an apocalyptic number.

138917856 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 138917856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (227332224).

138917856 is an abundant number, since it is smaller than the sum of its proper divisors (315746592).

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

138917856 is a wasteful number, since it uses less digits than its factorization.

138917856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18824 (or 18816 counting only the distinct ones).

The product of its digits is 362880, while the sum is 48.

The square root of 138917856 is about 11786.3419261449. The cubic root of 138917856 is about 517.9080848427.

The spelling of 138917856 in words is "one hundred thirty-eight million, nine hundred seventeen thousand, eight hundred fifty-six".