138443948591 has 4 divisors (see below), whose sum is σ = 149093483112. Its totient is φ = 127794414072.

The previous prime is 138443948579. The next prime is 138443948641. The reversal of 138443948591 is 195849344831.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-138443948591 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138443948591.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138443948501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5324767241 + ... + 5324767266.

It is an arithmetic number, because the mean of its divisors is an integer number (37273370778).

Almost surely, 2^138443948591 is an apocalyptic number.

138443948591 is a deficient number, since it is larger than the sum of its proper divisors (10649534521).

138443948591 is a wasteful number, since it uses less digits than its factorization.

138443948591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10649534520.

The product of its digits is 14929920, while the sum is 59.

The spelling of 138443948591 in words is "one hundred thirty-eight billion, four hundred forty-three million, nine hundred forty-eight thousand, five hundred ninety-one".