721680624 has 240 divisors, whose sum is σ = 2440439040. Its totient is φ = 203575680.

The previous prime is 721680611. The next prime is 721680677. The reversal of 721680624 is 426086127.

721680624 is a `hidden beast` number, since 7 + 21 + 6 + 8 + 0 + 624 = 666.

721680624 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2180139 + ... + 2180469.

It is an arithmetic number, because the mean of its divisors is an integer number (10168496).

Almost surely, 2^721680624 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 721680624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1220219520).

721680624 is an abundant number, since it is smaller than the sum of its proper divisors (1718758416).

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

721680624 is a wasteful number, since it uses less digits than its factorization.

721680624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465 (or 446 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 721680624 is about 26864.1140557436. The cubic root of 721680624 is about 896.9777737471.

The spelling of 721680624 in words is "seven hundred twenty-one million, six hundred eighty thousand, six hundred twenty-four".