681525720 has 96 divisors (see below), whose sum is σ = 2218881600. Its totient is φ = 181418496.

The previous prime is 681525703. The next prime is 681525721. The reversal of 681525720 is 27525186.

It is a happy number.

681525720 is a `hidden beast` number, since 6 + 81 + 5 + 2 + 572 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681525721) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 257524 + ... + 260156.

It is an arithmetic number, because the mean of its divisors is an integer number (23113350).

Almost surely, 2^681525720 is an apocalyptic number.

681525720 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 681525720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1109440800).

681525720 is an abundant number, since it is smaller than the sum of its proper divisors (1537355880).

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

681525720 is a wasteful number, since it uses less digits than its factorization.

681525720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3369 (or 3362 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The square root of 681525720 is about 26106.0475752267. The cubic root of 681525720 is about 880.0231226707.

The spelling of 681525720 in words is "six hundred eighty-one million, five hundred twenty-five thousand, seven hundred twenty".