72981705728 has 22 divisors (see below), whose sum is σ = 145892142306. Its totient is φ = 36490852352.

The previous prime is 72981705691. The next prime is 72981705737. The reversal of 72981705728 is 82750718927.

It can be written as a sum of positive squares in only one way, i.e., 52922082304 + 20059623424 = 230048^2 + 141632^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35634575 + ... + 35636622.

Almost surely, 2^72981705728 is an apocalyptic number.

It is an amenable number.

72981705728 is a deficient number, since it is larger than the sum of its proper divisors (72910436578).

72981705728 is an equidigital number, since it uses as much as digits as its factorization.

72981705728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71271217 (or 71271199 counting only the distinct ones).

The product of its (nonzero) digits is 3951360, while the sum is 56.

The spelling of 72981705728 in words is "seventy-two billion, nine hundred eighty-one million, seven hundred five thousand, seven hundred twenty-eight".