81940855911 has 8 divisors (see below), whose sum is σ = 109323498240. Its totient is φ = 54592725432.

The previous prime is 81940855897. The next prime is 81940855937. The reversal of 81940855911 is 11955804918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81940855911 - 2¹⁷ = 81940724839 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81940855991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8622421 + ... + 8631918.

It is an arithmetic number, because the mean of its divisors is an integer number (13665437280).

Almost surely, 2^81940855911 is an apocalyptic number.

81940855911 is a deficient number, since it is larger than the sum of its proper divisors (27382642329).

81940855911 is a wasteful number, since it uses less digits than its factorization.

81940855911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17255925.

The product of its (nonzero) digits is 518400, while the sum is 51.

The spelling of 81940855911 in words is "eighty-one billion, nine hundred forty million, eight hundred fifty-five thousand, nine hundred eleven".