138426444 has 144 divisors (see below), whose sum is σ = 405070848. Its totient is φ = 39481344.

The previous prime is 138426413. The next prime is 138426493. The reversal of 138426444 is 444624831.

138426444 is a `hidden beast` number, since 1 + 3 + 8 + 4 + 2 + 644 + 4 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 138426399 and 138426408.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1010344 + ... + 1010480.

It is an arithmetic number, because the mean of its divisors is an integer number (2812992).

Almost surely, 2^138426444 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138426444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (202535424).

138426444 is an abundant number, since it is smaller than the sum of its proper divisors (266644404).

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

138426444 is a wasteful number, since it uses less digits than its factorization.

138426444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304 (or 299 counting only the distinct ones).

The product of its digits is 73728, while the sum is 36.

The square root of 138426444 is about 11765.4767859190. The cubic root of 138426444 is about 517.2966757085.

The spelling of 138426444 in words is "one hundred thirty-eight million, four hundred twenty-six thousand, four hundred forty-four".