72640240640 has 176 divisors, whose sum is σ = 200100309120. Its totient is φ = 25024020480.

The previous prime is 72640240529. The next prime is 72640240657. The reversal of 72640240640 is 4604204627.

It is a tau number, because it is divible by the number of its divisors (176).

It is a self number, because there is not a number n which added to its sum of digits gives 72640240640.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1036139 + ... + 1104021.

Almost surely, 2^72640240640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72640240640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100050154560).

72640240640 is an abundant number, since it is smaller than the sum of its proper divisors (127460068480).

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

72640240640 is a wasteful number, since it uses less digits than its factorization.

72640240640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67938 (or 67920 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 35.

The spelling of 72640240640 in words is "seventy-two billion, six hundred forty million, two hundred forty thousand, six hundred forty".