81544915011 has 16 divisors (see below), whose sum is σ = 126794816000. Its totient is φ = 46597093704.

The previous prime is 81544915003. The next prime is 81544915031. The reversal of 81544915011 is 11051944518.

It is not a de Polignac number, because 81544915011 - 2³ = 81544915003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81544915031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39622351 + ... + 39624408.

It is an arithmetic number, because the mean of its divisors is an integer number (7924676000).

Almost surely, 2^81544915011 is an apocalyptic number.

81544915011 is a deficient number, since it is larger than the sum of its proper divisors (45249900989).

81544915011 is an equidigital number, since it uses as much as digits as its factorization.

81544915011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79246783 (or 79246769 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 39.

The spelling of 81544915011 in words is "eighty-one billion, five hundred forty-four million, nine hundred fifteen thousand, eleven".