7721712720 has 320 divisors, whose sum is σ = 28352471040. Its totient is φ = 1927107072.

The previous prime is 7721712683. The next prime is 7721712763. The reversal of 7721712720 is 272171277.

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 pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2333307 + ... + 2336613.

It is an arithmetic number, because the mean of its divisors is an integer number (88601472).

Almost surely, 2^7721712720 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 7721712720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14176235520).

7721712720 is an abundant number, since it is smaller than the sum of its proper divisors (20630758320).

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

7721712720 is a wasteful number, since it uses less digits than its factorization.

7721712720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3399 (or 3387 counting only the distinct ones).

The product of its (nonzero) digits is 19208, while the sum is 36.

The square root of 7721712720 is about 87873.2764838093. The cubic root of 7721712720 is about 1976.5351708714.

Adding to 7721712720 its reverse (272171277), we get a palindrome (7993883997).

The spelling of 7721712720 in words is "seven billion, seven hundred twenty-one million, seven hundred twelve thousand, seven hundred twenty".