72066557556 has 144 divisors (see below), whose sum is σ = 225815990400. Its totient is φ = 18906531840.

The previous prime is 72066557513. The next prime is 72066557569. The reversal of 72066557556 is 65575566027.

It is a happy number.

72066557556 is a `hidden beast` number, since 7 + 2 + 0 + 6 + 65 + 575 + 5 + 6 = 666.

It is a congruent number.

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, 29506 + ... + 380793.

It is an arithmetic number, because the mean of its divisors is an integer number (1568166600).

Almost surely, 2^72066557556 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 72066557556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112907995200).

72066557556 is an abundant number, since it is smaller than the sum of its proper divisors (153749432844).

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

72066557556 is a wasteful number, since it uses less digits than its factorization.

72066557556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410374 (or 410369 counting only the distinct ones).

The product of its (nonzero) digits is 13230000, while the sum is 54.

The spelling of 72066557556 in words is "seventy-two billion, sixty-six million, five hundred fifty-seven thousand, five hundred fifty-six".