681836544 has 171 divisors, whose sum is σ = 2092429417. Its totient is φ = 213909504.

The previous prime is 681836471. The next prime is 681836611. The reversal of 681836544 is 445638186.

The square root of 681836544 is 26112.

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

681836544 is a `hidden beast` number, since 68 + 18 + 36 + 544 = 666.

It can be written as a sum of positive squares in only one way, i.e., 530841600 + 150994944 = 23040^2 + 12288^2 .

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 681836544.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 40108024 + ... + 40108040.

Almost surely, 2^681836544 is an apocalyptic number.

681836544 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

681836544 is the 26112-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681836544

681836544 is an abundant number, since it is smaller than the sum of its proper divisors (1410592873).

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

681836544 is an frugal number, since it uses more digits than its factorization.

681836544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76 (or 22 counting only the distinct ones).

The product of its digits is 552960, while the sum is 45.

The cubic root of 681836544 is about 880.1568866291.

It can be divided in two parts, 681 and 836544, that added together give a square (837225 = 915²).

The spelling of 681836544 in words is "six hundred eighty-one million, eight hundred thirty-six thousand, five hundred forty-four".