138442291 has 4 divisors (see below), whose sum is σ = 149091712. Its totient is φ = 127792872.

The previous prime is 138442279. The next prime is 138442321. The reversal of 138442291 is 192244831.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 138442291 - 2⁷ = 138442163 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138442231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5324691 + ... + 5324716.

It is an arithmetic number, because the mean of its divisors is an integer number (37272928).

Almost surely, 2^138442291 is an apocalyptic number.

138442291 is a deficient number, since it is larger than the sum of its proper divisors (10649421).

138442291 is a wasteful number, since it uses less digits than its factorization.

138442291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10649420.

The product of its digits is 13824, while the sum is 34.

The square root of 138442291 is about 11766.1502200167. The cubic root of 138442291 is about 517.3164149225.

The spelling of 138442291 in words is "one hundred thirty-eight million, four hundred forty-two thousand, two hundred ninety-one".