81201415681 has 8 divisors (see below), whose sum is σ = 82386849600. Its totient is φ = 80017141680.

The previous prime is 81201415663. The next prime is 81201415697. The reversal of 81201415681 is 18651410218.

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 81201415681 - 2¹¹ = 81201413633 is a prime.

It is a super-3 number, since 3×81201415681³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81201415681.

It is not an unprimeable number, because it can be changed into a prime (81201415651) 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 7 ways as a sum of consecutive naturals, for example, 148446 + ... + 429463.

It is an arithmetic number, because the mean of its divisors is an integer number (10298356200).

Almost surely, 2^81201415681 is an apocalyptic number.

It is an amenable number.

81201415681 is a deficient number, since it is larger than the sum of its proper divisors (1185433919).

81201415681 is a wasteful number, since it uses less digits than its factorization.

81201415681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579959.

The product of its (nonzero) digits is 15360, while the sum is 37.

Adding to 81201415681 its reverse (18651410218), we get a palindrome (99852825899).

The spelling of 81201415681 in words is "eighty-one billion, two hundred one million, four hundred fifteen thousand, six hundred eighty-one".