81166541153 has 4 divisors (see below), whose sum is σ = 81186346800. Its totient is φ = 81146735508.

The previous prime is 81166541143. The next prime is 81166541167. The reversal of 81166541153 is 35114566118.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81166541153 - 2¹⁰ = 81166540129 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 81166541153.

It is not an unprimeable number, because it can be changed into a prime (81166541143) 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, 9896675 + ... + 9904872.

It is an arithmetic number, because the mean of its divisors is an integer number (20296586700).

Almost surely, 2^81166541153 is an apocalyptic number.

It is an amenable number.

81166541153 is a deficient number, since it is larger than the sum of its proper divisors (19805647).

81166541153 is a wasteful number, since it uses less digits than its factorization.

81166541153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19805646.

The product of its digits is 86400, while the sum is 41.

The spelling of 81166541153 in words is "eighty-one billion, one hundred sixty-six million, five hundred forty-one thousand, one hundred fifty-three".