138440944158 has 64 divisors (see below), whose sum is σ = 323949715200. Its totient is φ = 38993909760.

The previous prime is 138440944151. The next prime is 138440944171. The reversal of 138440944158 is 851449044831.

It is a self number, because there is not a number n which added to its sum of digits gives 138440944158.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138440944151) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 975043 + ... + 1107966.

It is an arithmetic number, because the mean of its divisors is an integer number (5061714300).

Almost surely, 2^138440944158 is an apocalyptic number.

138440944158 is an abundant number, since it is smaller than the sum of its proper divisors (185508771042).

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

138440944158 is a wasteful number, since it uses less digits than its factorization.

138440944158 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2083097.

The product of its (nonzero) digits is 2211840, while the sum is 51.

Adding to 138440944158 its reverse (851449044831), we get a palindrome (989889988989).

The spelling of 138440944158 in words is "one hundred thirty-eight billion, four hundred forty million, nine hundred forty-four thousand, one hundred fifty-eight".