681891665774 has 8 divisors (see below), whose sum is σ = 1115822725848. Its totient is φ = 309950757160.

The previous prime is 681891665771. The next prime is 681891665789. The reversal of 681891665774 is 477566198186.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681891665771) 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 3 ways as a sum of consecutive naturals, for example, 15497537837 + ... + 15497537880.

It is an arithmetic number, because the mean of its divisors is an integer number (139477840731).

Almost surely, 2^681891665774 is an apocalyptic number.

681891665774 is a deficient number, since it is larger than the sum of its proper divisors (433931060074).

681891665774 is a wasteful number, since it uses less digits than its factorization.

681891665774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30995075730.

The product of its digits is 121927680, while the sum is 68.

The spelling of 681891665774 in words is "six hundred eighty-one billion, eight hundred ninety-one million, six hundred sixty-five thousand, seven hundred seventy-four".