81326133441751 has 4 divisors (see below), whose sum is σ = 88719418300104. Its totient is φ = 73932848583400.

The previous prime is 81326133441689. The next prime is 81326133441881. The reversal of 81326133441751 is 15714433162318.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81326133441751 - 2⁹ = 81326133441239 is a prime.

It is a super-2 number, since 2×81326133441751² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81326133441695 and 81326133441704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81326133441251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3696642429160 + ... + 3696642429181.

It is an arithmetic number, because the mean of its divisors is an integer number (22179854575026).

Almost surely, 2^{81326133441751} is an apocalyptic number.

81326133441751 is a deficient number, since it is larger than the sum of its proper divisors (7393284858353).

81326133441751 is a wasteful number, since it uses less digits than its factorization.

81326133441751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7393284858352.

The product of its digits is 1451520, while the sum is 49.

The spelling of 81326133441751 in words is "eighty-one trillion, three hundred twenty-six billion, one hundred thirty-three million, four hundred forty-one thousand, seven hundred fifty-one".