721687552 has 66 divisors (see below), whose sum is σ = 1473852282. Its totient is φ = 353193984.

The previous prime is 721687531. The next prime is 721687607. The reversal of 721687552 is 255786127.

It can be written as a sum of positive squares in only one way, i.e., 556205056 + 165482496 = 23584^2 + 12864^2 .

It is a junction number, because it is equal to n+sod(n) for n = 721687499 and 721687508.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4596658 + ... + 4596814.

Almost surely, 2^721687552 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 721687552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (736926141).

721687552 is an abundant number, since it is smaller than the sum of its proper divisors (752164730).

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

721687552 is an equidigital number, since it uses as much as digits as its factorization.

721687552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311 (or 226 counting only the distinct ones).

The product of its digits is 235200, while the sum is 43.

The square root of 721687552 is about 26864.2430006877. The cubic root of 721687552 is about 896.9806440113.

The spelling of 721687552 in words is "seven hundred twenty-one million, six hundred eighty-seven thousand, five hundred fifty-two".