81662881916877 has 8 divisors (see below), whose sum is σ = 111200520057216. Its totient is φ = 53283582527232.

The previous prime is 81662881916873. The next prime is 81662881916887. The reversal of 81662881916877 is 77861918826618.

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

It is not a de Polignac number, because 81662881916877 - 2² = 81662881916873 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81662881916873) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 289584687508 + ... + 289584687789.

It is an arithmetic number, because the mean of its divisors is an integer number (13900065007152).

Almost surely, 2^{81662881916877} is an apocalyptic number.

It is an amenable number.

81662881916877 is a deficient number, since it is larger than the sum of its proper divisors (29537638140339).

81662881916877 is a wasteful number, since it uses less digits than its factorization.

81662881916877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 579169375347.

The product of its digits is 780337152, while the sum is 78.

The spelling of 81662881916877 in words is "eighty-one trillion, six hundred sixty-two billion, eight hundred eighty-one million, nine hundred sixteen thousand, eight hundred seventy-seven".