681763502821 has 32 divisors (see below), whose sum is σ = 732532792320. Its totient is φ = 632992690176.

The previous prime is 681763502711. The next prime is 681763502831. The reversal of 681763502821 is 128205367186.

It is a happy number.

It is not a de Polignac number, because 681763502821 - 2⁹ = 681763502309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681763502831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 279754015 + ... + 279756451.

It is an arithmetic number, because the mean of its divisors is an integer number (22891649760).

Almost surely, 2^681763502821 is an apocalyptic number.

It is an amenable number.

681763502821 is a deficient number, since it is larger than the sum of its proper divisors (50769289499).

681763502821 is a wasteful number, since it uses less digits than its factorization.

681763502821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4533.

The product of its (nonzero) digits is 967680, while the sum is 49.

The spelling of 681763502821 in words is "six hundred eighty-one billion, seven hundred sixty-three million, five hundred two thousand, eight hundred twenty-one".