72609218640 has 640 divisors, whose sum is σ = 302637772800. Its totient is φ = 15647385600.

The previous prime is 72609218639. The next prime is 72609218651. The reversal of 72609218640 is 4681290627.

It is a happy number.

It is a super-2 number, since 2×72609218640² (a number of 23 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 18852715 + ... + 18856565.

It is an arithmetic number, because the mean of its divisors is an integer number (472871520).

Almost surely, 2^72609218640 is an apocalyptic number.

72609218640 is a gapful number since it is divisible by the number (70) 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 72609218640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151318886400).

72609218640 is an abundant number, since it is smaller than the sum of its proper divisors (230028554160).

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

72609218640 is a wasteful number, since it uses less digits than its factorization.

72609218640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3952 (or 3940 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The spelling of 72609218640 in words is "seventy-two billion, six hundred nine million, two hundred eighteen thousand, six hundred forty".