81543268405 has 16 divisors (see below), whose sum is σ = 101937528000. Its totient is φ = 62564813440.

The previous prime is 81543268381. The next prime is 81543268421. The reversal of 81543268405 is 50486234518.

It is not a de Polignac number, because 81543268405 - 2⁹ = 81543267893 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3358855 + ... + 3383044.

It is an arithmetic number, because the mean of its divisors is an integer number (6371095500).

Almost surely, 2^81543268405 is an apocalyptic number.

It is an amenable number.

81543268405 is a deficient number, since it is larger than the sum of its proper divisors (20394259595).

81543268405 is a wasteful number, since it uses less digits than its factorization.

81543268405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6742004.

The product of its (nonzero) digits is 921600, while the sum is 46.

The spelling of 81543268405 in words is "eighty-one billion, five hundred forty-three million, two hundred sixty-eight thousand, four hundred five".