81954649510687 has 2 divisors, whose sum is σ = 81954649510688. Its totient is φ = 81954649510686.

The previous prime is 81954649510639. The next prime is 81954649510697. The reversal of 81954649510687 is 78601594645918.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81954649510687 - 2¹¹ = 81954649508639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81954649510627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40977324755343 + 40977324755344.

It is an arithmetic number, because the mean of its divisors is an integer number (40977324755344).

Almost surely, 2^{81954649510687} is an apocalyptic number.

81954649510687 is a deficient number, since it is larger than the sum of its proper divisors (1).

81954649510687 is an equidigital number, since it uses as much as digits as its factorization.

81954649510687 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 522547200, while the sum is 73.

The spelling of 81954649510687 in words is "eighty-one trillion, nine hundred fifty-four billion, six hundred forty-nine million, five hundred ten thousand, six hundred eighty-seven".