138436242 has 64 divisors (see below), whose sum is σ = 334801920. Its totient is φ = 37278144.

The previous prime is 138436237. The next prime is 138436283. The reversal of 138436242 is 242634831.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 225528 + ... + 226140.

It is an arithmetic number, because the mean of its divisors is an integer number (5231280).

Almost surely, 2^138436242 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138436242, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167400960).

138436242 is an abundant number, since it is smaller than the sum of its proper divisors (196365678).

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

138436242 is a wasteful number, since it uses less digits than its factorization.

138436242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 927.

The product of its digits is 27648, while the sum is 33.

The square root of 138436242 is about 11765.8931662666. The cubic root of 138436242 is about 517.3088803930.

The spelling of 138436242 in words is "one hundred thirty-eight million, four hundred thirty-six thousand, two hundred forty-two".