721721456 has 20 divisors (see below), whose sum is σ = 1398775800. Its totient is φ = 360747072.

The previous prime is 721721449. The next prime is 721721467. The reversal of 721721456 is 654127127.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71915 + ... + 81333.

It is an arithmetic number, because the mean of its divisors is an integer number (69938790).

Almost surely, 2^721721456 is an apocalyptic number.

It is an amenable number.

721721456 is a deficient number, since it is larger than the sum of its proper divisors (677054344).

721721456 is a wasteful number, since it uses less digits than its factorization.

721721456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14216 (or 14210 counting only the distinct ones).

The product of its digits is 23520, while the sum is 35.

The square root of 721721456 is about 26864.8740179440. The cubic root of 721721456 is about 896.9946901431.

The spelling of 721721456 in words is "seven hundred twenty-one million, seven hundred twenty-one thousand, four hundred fifty-six".