681444436 has 24 divisors (see below), whose sum is σ = 1263747240. Its totient is φ = 320947200.

The previous prime is 681444433. The next prime is 681444461. The reversal of 681444436 is 634444186.

It can be written as a sum of positive squares in 4 ways, for example, as 25060036 + 656384400 = 5006^2 + 25620^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681444433) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 66885 + ... + 76396.

It is an arithmetic number, because the mean of its divisors is an integer number (52656135).

Almost surely, 2^681444436 is an apocalyptic number.

It is an amenable number.

681444436 is a deficient number, since it is larger than the sum of its proper divisors (582302804).

681444436 is a wasteful number, since it uses less digits than its factorization.

681444436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143355 (or 143353 counting only the distinct ones).

The product of its digits is 221184, while the sum is 40.

The square root of 681444436 is about 26104.4907247776. The cubic root of 681444436 is about 879.9881351706.

The spelling of 681444436 in words is "six hundred eighty-one million, four hundred forty-four thousand, four hundred thirty-six".