721664052472 has 96 divisors (see below), whose sum is σ = 1581952997520. Its totient is φ = 305999912960.

The previous prime is 721664052349. The next prime is 721664052479. The reversal of 721664052472 is 274250466127.

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721664052479) 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 23 ways as a sum of consecutive naturals, for example, 2748258 + ... + 2999374.

Almost surely, 2^721664052472 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 721664052472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (790976498760).

721664052472 is an abundant number, since it is smaller than the sum of its proper divisors (860288945048).

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

721664052472 is a wasteful number, since it uses less digits than its factorization.

721664052472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251281 (or 251260 counting only the distinct ones).

The product of its (nonzero) digits is 1128960, while the sum is 46.

The spelling of 721664052472 in words is "seven hundred twenty-one billion, six hundred sixty-four million, fifty-two thousand, four hundred seventy-two".