138418722 has 48 divisors (see below), whose sum is σ = 329100408. Its totient is φ = 41783040.

The previous prime is 138418691. The next prime is 138418723. The reversal of 138418722 is 227814831.

It can be written as a sum of positive squares in 4 ways, for example, as 68211081 + 70207641 = 8259^2 + 8379^2 .

It is a super-2 number, since 2×138418722² = 38319485200226568, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138418723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6822 + ... + 17982.

Almost surely, 2^138418722 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138418722, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164550204).

138418722 is an abundant number, since it is smaller than the sum of its proper divisors (190681686).

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

138418722 is a wasteful number, since it uses less digits than its factorization.

138418722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11235 (or 11232 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 138418722 is about 11765.1486178458. The cubic root of 138418722 is about 517.2870565464.

The spelling of 138418722 in words is "one hundred thirty-eight million, four hundred eighteen thousand, seven hundred twenty-two".