138065840640 has 480 divisors, whose sum is σ = 588514582656. Its totient is φ = 29129932800.

The previous prime is 138065840623. The next prime is 138065840681. The reversal of 138065840640 is 46048560831.

138065840640 is a `hidden beast` number, since 1 + 3 + 8 + 0 + 6 + 584 + 0 + 64 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2063715 + ... + 2129565.

Almost surely, 2^138065840640 is an apocalyptic number.

138065840640 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 138065840640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (294257291328).

138065840640 is an abundant number, since it is smaller than the sum of its proper divisors (450448742016).

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

138065840640 is a wasteful number, since it uses less digits than its factorization.

138065840640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65900 (or 65881 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 45.

The spelling of 138065840640 in words is "one hundred thirty-eight billion, sixty-five million, eight hundred forty thousand, six hundred forty".