81446899163 has 4 divisors (see below), whose sum is σ = 93082170480. Its totient is φ = 69811627848.

The previous prime is 81446899141. The next prime is 81446899169. The reversal of 81446899163 is 36199864418.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81446899163 - 2²⁰ = 81445850587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81446899169) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5817635648 + ... + 5817635661.

It is an arithmetic number, because the mean of its divisors is an integer number (23270542620).

Almost surely, 2^81446899163 is an apocalyptic number.

81446899163 is a deficient number, since it is larger than the sum of its proper divisors (11635271317).

81446899163 is a wasteful number, since it uses less digits than its factorization.

81446899163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11635271316.

The product of its digits is 8957952, while the sum is 59.

The spelling of 81446899163 in words is "eighty-one billion, four hundred forty-six million, eight hundred ninety-nine thousand, one hundred sixty-three".