720731520 has 160 divisors (see below), whose sum is σ = 2574047520. Its totient is φ = 192181248.

The previous prime is 720731483. The next prime is 720731521. The reversal of 720731520 is 25137027.

720731520 is a `hidden beast` number, since 72 + 0 + 73 + 1 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720731521) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 44889 + ... + 58791.

It is an arithmetic number, because the mean of its divisors is an integer number (16087797).

Almost surely, 2^720731520 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 720731520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1287023760).

720731520 is an abundant number, since it is smaller than the sum of its proper divisors (1853316000).

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

720731520 is a wasteful number, since it uses less digits than its factorization.

720731520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13934 (or 13913 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 27.

The square root of 720731520 is about 26846.4433398542. The cubic root of 720731520 is about 896.5843870519.

Adding to 720731520 its reverse (25137027), we get a palindrome (745868547).

The spelling of 720731520 in words is "seven hundred twenty million, seven hundred thirty-one thousand, five hundred twenty".