81958885885 has 16 divisors (see below), whose sum is σ = 99102326400. Its totient is φ = 65067869376.

The previous prime is 81958885871. The next prime is 81958885889. The reversal of 81958885885 is 58858885918.

It is a cyclic number.

It is not a de Polignac number, because 81958885885 - 2⁹ = 81958885373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81958885889) 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, 234936 + ... + 468094.

It is an arithmetic number, because the mean of its divisors is an integer number (6193895400).

Almost surely, 2^81958885885 is an apocalyptic number.

It is an amenable number.

81958885885 is a deficient number, since it is larger than the sum of its proper divisors (17143440515).

81958885885 is a wasteful number, since it uses less digits than its factorization.

81958885885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233700.

The product of its digits is 294912000, while the sum is 73.

The spelling of 81958885885 in words is "eighty-one billion, nine hundred fifty-eight million, eight hundred eighty-five thousand, eight hundred eighty-five".