681181812 has 60 divisors (see below), whose sum is σ = 1842174180. Its totient is φ = 219227904.

The previous prime is 681181801. The next prime is 681181843. The reversal of 681181812 is 218181186.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 290566116 + 390615696 = 17046^2 + 19764^2 .

It is a super-4 number, since 4×681181812⁴ (a number of 36 digits) contains 4444 as substring.

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

It is a congruent number.

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 26853 + ... + 45644.

It is an arithmetic number, because the mean of its divisors is an integer number (30702903).

Almost surely, 2^681181812 is an apocalyptic number.

It is an amenable number.

681181812 is an abundant number, since it is smaller than the sum of its proper divisors (1160992368).

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

681181812 is a wasteful number, since it uses less digits than its factorization.

681181812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72542 (or 72531 counting only the distinct ones).

The product of its digits is 6144, while the sum is 36.

The square root of 681181812 is about 26099.4599944137. The cubic root of 681181812 is about 879.8750735195.

The spelling of 681181812 in words is "six hundred eighty-one million, one hundred eighty-one thousand, eight hundred twelve".