681001871781 has 64 divisors (see below), whose sum is σ = 1143004317696. Its totient is φ = 350350694400.

The previous prime is 681001871723. The next prime is 681001871831. The reversal of 681001871781 is 187178100186.

It is not a de Polignac number, because 681001871781 - 2⁷ = 681001871653 is a prime.

It is a super-2 number, since 2×681001871781² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 681001871781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681001871281) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 34106641 + ... + 34126601.

It is an arithmetic number, because the mean of its divisors is an integer number (17859442464).

Almost surely, 2^681001871781 is an apocalyptic number.

It is an amenable number.

681001871781 is a deficient number, since it is larger than the sum of its proper divisors (462002445915).

681001871781 is a wasteful number, since it uses less digits than its factorization.

681001871781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21402.

The product of its (nonzero) digits is 150528, while the sum is 48.

The spelling of 681001871781 in words is "six hundred eighty-one billion, one million, eight hundred seventy-one thousand, seven hundred eighty-one".