81218884177 has 8 divisors (see below), whose sum is σ = 81852039360. Its totient is φ = 80587756080.

The previous prime is 81218884129. The next prime is 81218884193. The reversal of 81218884177 is 77148881218.

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

It is a cyclic number.

It is not a de Polignac number, because 81218884177 - 2¹⁵ = 81218851409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81218684177) 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, 426277 + ... + 586642.

It is an arithmetic number, because the mean of its divisors is an integer number (10231504920).

Almost surely, 2^81218884177 is an apocalyptic number.

It is an amenable number.

81218884177 is a deficient number, since it is larger than the sum of its proper divisors (633155183).

81218884177 is a wasteful number, since it uses less digits than its factorization.

81218884177 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1013543.

The product of its digits is 1605632, while the sum is 55.

The spelling of 81218884177 in words is "eighty-one billion, two hundred eighteen million, eight hundred eighty-four thousand, one hundred seventy-seven".