688572720 has 240 divisors, whose sum is σ = 2540408832. Its totient is φ = 165757440.

The previous prime is 688572691. The next prime is 688572727. The reversal of 688572720 is 27275886.

688572720 is a `hidden beast` number, since 6 + 8 + 8 + 572 + 72 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (688572727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1797649 + ... + 1798031.

Almost surely, 2^688572720 is an apocalyptic number.

688572720 is a gapful number since it is divisible by the number (60) 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 688572720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1270204416).

688572720 is an abundant number, since it is smaller than the sum of its proper divisors (1851836112).

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

688572720 is a wasteful number, since it uses less digits than its factorization.

688572720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640 (or 631 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 45.

The square root of 688572720 is about 26240.6691987838. The cubic root of 688572720 is about 883.0458847150.

The spelling of 688572720 in words is "six hundred eighty-eight million, five hundred seventy-two thousand, seven hundred twenty".