721571328 has 200 divisors, whose sum is σ = 2186502912. Its totient is φ = 236888064.

The previous prime is 721571321. The next prime is 721571329. The reversal of 721571328 is 823175127.

It is a Harshad number since it is a multiple of its sum of digits (36).

Its product of digits (23520) is a multiple of the sum of its prime factors (294).

It is a junction number, because it is equal to n+sod(n) for n = 721571292 and 721571301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721571321) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5266876 + ... + 5267012.

Almost surely, 2^721571328 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 721571328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1093251456).

721571328 is an abundant number, since it is smaller than the sum of its proper divisors (1464931584).

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

721571328 is a wasteful number, since it uses less digits than its factorization.

721571328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 294 (or 269 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The square root of 721571328 is about 26862.0797407796. The cubic root of 721571328 is about 896.9324900814.

The spelling of 721571328 in words is "seven hundred twenty-one million, five hundred seventy-one thousand, three hundred twenty-eight".