681732100 has 81 divisors (see below), whose sum is σ = 1725512607. Its totient is φ = 233110080.

The previous prime is 681732089. The next prime is 681732109. The reversal of 681732100 is 1237186.

The square root of 681732100 is 26110.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 6563844 + 675168256 = 2562^2 + 25984^2 .

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (681732109) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1827514 + ... + 1827886.

Almost surely, 2^681732100 is an apocalyptic number.

681732100 is the 26110-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681732100

681732100 is an abundant number, since it is smaller than the sum of its proper divisors (1043780507).

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

681732100 is a wasteful number, since it uses less digits than its factorization.

681732100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 774 (or 387 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 28.

The cubic root of 681732100 is about 880.1119434039. Note that the first 3 decimals are identical.

Adding to 681732100 its reverse (1237186), we get a palindrome (682969286).

The spelling of 681732100 in words is "six hundred eighty-one million, seven hundred thirty-two thousand, one hundred".