681774521602 has 12 divisors (see below), whose sum is σ = 1079318946006. Its totient is φ = 322945825680.

The previous prime is 681774521599. The next prime is 681774521611. The reversal of 681774521602 is 206125477186.

It can be written as a sum of positive squares in only one way, i.e., 395730323041 + 286044198561 = 629071^2 + 534831^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 472142299 + ... + 472143742.

Almost surely, 2^681774521602 is an apocalyptic number.

681774521602 is a deficient number, since it is larger than the sum of its proper divisors (397544424404).

681774521602 is a wasteful number, since it uses less digits than its factorization.

681774521602 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 944286081 (or 944286062 counting only the distinct ones).

The product of its (nonzero) digits is 1128960, while the sum is 49.

Adding to 681774521602 its reverse (206125477186), we get a palindrome (887899998788).

The spelling of 681774521602 in words is "six hundred eighty-one billion, seven hundred seventy-four million, five hundred twenty-one thousand, six hundred two".