721681596 has 96 divisors (see below), whose sum is σ = 1931074880. Its totient is φ = 232906752.

The previous prime is 721681591. The next prime is 721681607. The reversal of 721681596 is 695186127.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721681591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1250460 + ... + 1251036.

Almost surely, 2^721681596 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 721681596, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (965537440).

721681596 is an abundant number, since it is smaller than the sum of its proper divisors (1209393284).

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

721681596 is a wasteful number, since it uses less digits than its factorization.

721681596 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 940 (or 932 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 721681596 is about 26864.1321467864. The cubic root of 721681596 is about 896.9781764469.

The spelling of 721681596 in words is "seven hundred twenty-one million, six hundred eighty-one thousand, five hundred ninety-six".