681222528 has 256 divisors, whose sum is σ = 2379456000. Its totient is φ = 187729920.

The previous prime is 681222511. The next prime is 681222541. The reversal of 681222528 is 825222186.

681222528 is a `hidden beast` number, since 6 + 8 + 122 + 2 + 528 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 681222492 and 681222501.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 701083 + ... + 702053.

It is an arithmetic number, because the mean of its divisors is an integer number (9294750).

Almost surely, 2^681222528 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 681222528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1189728000).

681222528 is an abundant number, since it is smaller than the sum of its proper divisors (1698233472).

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

681222528 is a wasteful number, since it uses less digits than its factorization.

681222528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1030 (or 1012 counting only the distinct ones).

The product of its digits is 30720, while the sum is 36.

The square root of 681222528 is about 26100.2399988966. The cubic root of 681222528 is about 879.8926039737.

The spelling of 681222528 in words is "six hundred eighty-one million, two hundred twenty-two thousand, five hundred twenty-eight".