721380840 has 64 divisors (see below), whose sum is σ = 2165909760. Its totient is φ = 192211200.

The previous prime is 721380799. The next prime is 721380841. The reversal of 721380840 is 48083127.

It is not an unprimeable number, because it can be changed into a prime (721380841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 280842 + ... + 283398.

It is an arithmetic number, because the mean of its divisors is an integer number (33842340).

Almost surely, 2^721380840 is an apocalyptic number.

It is an amenable number.

721380840 is an abundant number, since it is smaller than the sum of its proper divisors (1444528920).

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

721380840 is a wasteful number, since it uses less digits than its factorization.

721380840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4922 (or 4918 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 33.

The square root of 721380840 is about 26858.5338393591. The cubic root of 721380840 is about 896.8535559062.

The spelling of 721380840 in words is "seven hundred twenty-one million, three hundred eighty thousand, eight hundred forty".