138401568 has 96 divisors (see below), whose sum is σ = 413622720. Its totient is φ = 44997120.

The previous prime is 138401561. The next prime is 138401579. The reversal of 138401568 is 865104831.

138401568 is a `hidden beast` number, since 13 + 84 + 0 + 1 + 568 = 666.

138401568 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 (36).

It is not an unprimeable number, because it can be changed into a prime (138401561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33471 + ... + 37377.

It is an arithmetic number, because the mean of its divisors is an integer number (4308570).

Almost surely, 2^138401568 is an apocalyptic number.

138401568 is a gapful number since it is divisible by the number (18) 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 138401568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (206811360).

138401568 is an abundant number, since it is smaller than the sum of its proper divisors (275221152).

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

138401568 is a wasteful number, since it uses less digits than its factorization.

138401568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3967 (or 3953 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 138401568 is about 11764.4195776927. The cubic root of 138401568 is about 517.2656868246.

The spelling of 138401568 in words is "one hundred thirty-eight million, four hundred one thousand, five hundred sixty-eight".