81580945911 has 8 divisors (see below), whose sum is σ = 109007518464. Its totient is φ = 54270835320.

The previous prime is 81580945891. The next prime is 81580945921. The reversal of 81580945911 is 11954908518.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81580945911 - 2⁹ = 81580945399 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81580945921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29113855 + ... + 29116656.

It is an arithmetic number, because the mean of its divisors is an integer number (13625939808).

Almost surely, 2^81580945911 is an apocalyptic number.

81580945911 is a deficient number, since it is larger than the sum of its proper divisors (27426572553).

81580945911 is a wasteful number, since it uses less digits than its factorization.

81580945911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58230981.

The product of its (nonzero) digits is 518400, while the sum is 51.

The spelling of 81580945911 in words is "eighty-one billion, five hundred eighty million, nine hundred forty-five thousand, nine hundred eleven".