9072721920 has 480 divisors, whose sum is σ = 32085446400. Its totient is φ = 2179989504.

The previous prime is 9072721913. The next prime is 9072721943. The reversal of 9072721920 is 291272709.

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 135413727 + ... + 135413793.

It is an arithmetic number, because the mean of its divisors is an integer number (66844680).

Almost surely, 2^9072721920 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 9072721920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16042723200).

9072721920 is an abundant number, since it is smaller than the sum of its proper divisors (23012724480).

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

9072721920 is a wasteful number, since it uses less digits than its factorization.

9072721920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151 (or 125 counting only the distinct ones).

The product of its (nonzero) digits is 31752, while the sum is 39.

The square root of 9072721920 is about 95250.8368467175. The cubic root of 9072721920 is about 2085.6713076240.

The spelling of 9072721920 in words is "nine billion, seventy-two million, seven hundred twenty-one thousand, nine hundred twenty".