138661389174 has 128 divisors (see below), whose sum is σ = 351373492224. Its totient is φ = 35730525600.

The previous prime is 138661389161. The next prime is 138661389179. The reversal of 138661389174 is 471983166831.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138661389179) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7089789 + ... + 7109319.

It is an arithmetic number, because the mean of its divisors is an integer number (2745105408).

Almost surely, 2^138661389174 is an apocalyptic number.

138661389174 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 138661389174, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (175686746112).

138661389174 is an abundant number, since it is smaller than the sum of its proper divisors (212712103050).

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

138661389174 is a wasteful number, since it uses less digits than its factorization.

138661389174 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19703 (or 19681 counting only the distinct ones).

The product of its digits is 5225472, while the sum is 57.

The spelling of 138661389174 in words is "one hundred thirty-eight billion, six hundred sixty-one million, three hundred eighty-nine thousand, one hundred seventy-four".