81035870191 has 2 divisors, whose sum is σ = 81035870192. Its totient is φ = 81035870190.

The previous prime is 81035870177. The next prime is 81035870221. The reversal of 81035870191 is 19107853018.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81035870191 - 2⁵ = 81035870159 is a prime.

It is a super-2 number, since 2×81035870191² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81035870101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40517935095 + 40517935096.

It is an arithmetic number, because the mean of its divisors is an integer number (40517935096).

Almost surely, 2^81035870191 is an apocalyptic number.

81035870191 is a deficient number, since it is larger than the sum of its proper divisors (1).

81035870191 is an equidigital number, since it uses as much as digits as its factorization.

81035870191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60480, while the sum is 43.

The spelling of 81035870191 in words is "eighty-one billion, thirty-five million, eight hundred seventy thousand, one hundred ninety-one".