721721818680 has 32 divisors (see below), whose sum is σ = 2165165456400. Its totient is φ = 192459151616.

The previous prime is 721721818633. The next prime is 721721818709. The reversal of 721721818680 is 86818127127.

721721818680 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3007174125 + ... + 3007174364.

Almost surely, 2^721721818680 is an apocalyptic number.

It is an amenable number.

721721818680 is an abundant number, since it is smaller than the sum of its proper divisors (1443443637720).

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

721721818680 is a wasteful number, since it uses less digits than its factorization.

721721818680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6014348503 (or 6014348499 counting only the distinct ones).

The product of its (nonzero) digits is 602112, while the sum is 51.

The spelling of 721721818680 in words is "seven hundred twenty-one billion, seven hundred twenty-one million, eight hundred eighteen thousand, six hundred eighty".