8130191681 has 4 divisors (see below), whose sum is σ = 8267991600. Its totient is φ = 7992391764.

The previous prime is 8130191669. The next prime is 8130191683. The reversal of 8130191681 is 1861910318.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 8130191681 - 2⁶ = 8130191617 is a prime.

It is a super-2 number, since 2×8130191681² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8130191683) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68899871 + ... + 68899988.

It is an arithmetic number, because the mean of its divisors is an integer number (2066997900).

Almost surely, 2^8130191681 is an apocalyptic number.

It is an amenable number.

8130191681 is a deficient number, since it is larger than the sum of its proper divisors (137799919).

8130191681 is a wasteful number, since it uses less digits than its factorization.

8130191681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137799918.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 8130191681 is about 90167.5755524124. The cubic root of 8130191681 is about 2010.7909794184.

The spelling of 8130191681 in words is "eight billion, one hundred thirty million, one hundred ninety-one thousand, six hundred eighty-one".