721486656 has 112 divisors (see below), whose sum is σ = 2313919680. Its totient is φ = 218626560.

The previous prime is 721486651. The next prime is 721486657. The reversal of 721486656 is 656684127.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721486651) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30 + ... + 37986.

Almost surely, 2^721486656 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 721486656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1156959840).

721486656 is an abundant number, since it is smaller than the sum of its proper divisors (1592433024).

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

721486656 is a wasteful number, since it uses less digits than its factorization.

721486656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37989 (or 37973 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 721486656 is about 26860.5036438262. The cubic root of 721486656 is about 896.8974055210.

The spelling of 721486656 in words is "seven hundred twenty-one million, four hundred eighty-six thousand, six hundred fifty-six".