81954950237843 has 2 divisors, whose sum is σ = 81954950237844. Its totient is φ = 81954950237842.

The previous prime is 81954950237827. The next prime is 81954950237893. The reversal of 81954950237843 is 34873205945918.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81954950237843 - 2⁴ = 81954950237827 is a prime.

It is a super-2 number, since 2×81954950237843² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81954950237813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40977475118921 + 40977475118922.

It is an arithmetic number, because the mean of its divisors is an integer number (40977475118922).

Almost surely, 2^{81954950237843} is an apocalyptic number.

81954950237843 is a deficient number, since it is larger than the sum of its proper divisors (1).

81954950237843 is an equidigital number, since it uses as much as digits as its factorization.

81954950237843 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 261273600, while the sum is 68.

The spelling of 81954950237843 in words is "eighty-one trillion, nine hundred fifty-four billion, nine hundred fifty million, two hundred thirty-seven thousand, eight hundred forty-three".