81540210893 has 8 divisors (see below), whose sum is σ = 85855629600. Its totient is φ = 77227175088.

The previous prime is 81540210889. The next prime is 81540210929. The reversal of 81540210893 is 39801204518.

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 81540210893 - 2² = 81540210889 is a prime.

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 81540210893.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81540210823) 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, 525263 + ... + 662556.

It is an arithmetic number, because the mean of its divisors is an integer number (10731953700).

Almost surely, 2^81540210893 is an apocalyptic number.

It is an amenable number.

81540210893 is a deficient number, since it is larger than the sum of its proper divisors (4315418707).

81540210893 is a wasteful number, since it uses less digits than its factorization.

81540210893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1191451.

The product of its (nonzero) digits is 69120, while the sum is 41.

The spelling of 81540210893 in words is "eighty-one billion, five hundred forty million, two hundred ten thousand, eight hundred ninety-three".