721745500 has 144 divisors (see below), whose sum is σ = 1859850720. Its totient is φ = 243936000.

The previous prime is 721745491. The next prime is 721745537. The reversal of 721745500 is 5547127.

721745500 is digitally balanced in base 2 and base 6, because in such bases it contains all the possibile digits an equal number of times.

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, 2180335 + ... + 2180665.

It is an arithmetic number, because the mean of its divisors is an integer number (12915630).

Almost surely, 2^721745500 is an apocalyptic number.

721745500 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 721745500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (929925360).

721745500 is an abundant number, since it is smaller than the sum of its proper divisors (1138105220).

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

721745500 is a wasteful number, since it uses less digits than its factorization.

721745500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 453 (or 434 counting only the distinct ones).

The product of its (nonzero) digits is 9800, while the sum is 31.

The square root of 721745500 is about 26865.3215130584. The cubic root of 721745500 is about 897.0046510963.

The spelling of 721745500 in words is "seven hundred twenty-one million, seven hundred forty-five thousand, five hundred".