81011543667 has 16 divisors (see below), whose sum is σ = 113018864640. Its totient is φ = 51518757312.

The previous prime is 81011543659. The next prime is 81011543699. The reversal of 81011543667 is 76634511018.

It is not a de Polignac number, because 81011543667 - 2³ = 81011543659 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81016543667) by changing a digit.

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, 1574242 + ... + 1624887.

It is an arithmetic number, because the mean of its divisors is an integer number (7063679040).

Almost surely, 2^81011543667 is an apocalyptic number.

81011543667 is a deficient number, since it is larger than the sum of its proper divisors (32007320973).

81011543667 is a wasteful number, since it uses less digits than its factorization.

81011543667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3199522.

The product of its (nonzero) digits is 120960, while the sum is 42.

The spelling of 81011543667 in words is "eighty-one billion, eleven million, five hundred forty-three thousand, six hundred sixty-seven".