7724720640 has 480 divisors, whose sum is σ = 30956143680. Its totient is φ = 1628798976.

The previous prime is 7724720639. The next prime is 7724720659. The reversal of 7724720640 is 460274277.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (39).

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, 4891371 + ... + 4892949.

It is an arithmetic number, because the mean of its divisors is an integer number (64491966).

Almost surely, 2^7724720640 is an apocalyptic number.

7724720640 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7724720640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15478071840).

7724720640 is an abundant number, since it is smaller than the sum of its proper divisors (23231423040).

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

7724720640 is a wasteful number, since it uses less digits than its factorization.

7724720640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1632 (or 1609 counting only the distinct ones).

The product of its (nonzero) digits is 131712, while the sum is 39.

The square root of 7724720640 is about 87890.3899183523. The cubic root of 7724720640 is about 1976.7917844009.

The spelling of 7724720640 in words is "seven billion, seven hundred twenty-four million, seven hundred twenty thousand, six hundred forty".