721815318560 has 192 divisors, whose sum is σ = 2036363825664. Its totient is φ = 236402073600.

The previous prime is 721815318547. The next prime is 721815318563. The reversal of 721815318560 is 65813518127.

It is not an unprimeable number, because it can be changed into a prime (721815318563) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19584950 + ... + 19621770.

It is an arithmetic number, because the mean of its divisors is an integer number (10606061592).

Almost surely, 2^721815318560 is an apocalyptic number.

721815318560 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 721815318560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1018181912832).

721815318560 is an abundant number, since it is smaller than the sum of its proper divisors (1314548507104).

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

721815318560 is a wasteful number, since it uses less digits than its factorization.

721815318560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37627 (or 37619 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 47.

The spelling of 721815318560 in words is "seven hundred twenty-one billion, eight hundred fifteen million, three hundred eighteen thousand, five hundred sixty".