138433639680 has 1296 divisors, whose sum is σ = 598474566144. Its totient is φ = 30516756480.

The previous prime is 138433639637. The next prime is 138433639681. The reversal of 138433639680 is 86936334831.

138433639680 is a `hidden beast` number, since 138 + 43 + 3 + 6 + 396 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (1296).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138433639681) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 472469614 + ... + 472469906.

Almost surely, 2^138433639680 is an apocalyptic number.

138433639680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138433639680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (299237283072).

138433639680 is an abundant number, since it is smaller than the sum of its proper divisors (460040926464).

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

138433639680 is an equidigital number, since it uses as much as digits as its factorization.

138433639680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374 (or 341 counting only the distinct ones).

The product of its (nonzero) digits is 6718464, while the sum is 54.

The spelling of 138433639680 in words is "one hundred thirty-eight billion, four hundred thirty-three million, six hundred thirty-nine thousand, six hundred eighty".