81481708711 has 4 divisors (see below), whose sum is σ = 87749532472. Its totient is φ = 75213884952.

The previous prime is 81481708687. The next prime is 81481708723. The reversal of 81481708711 is 11780718418.

It is a happy number.

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 81481708711 - 2³³ = 72891774119 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81481708751) 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, 3133911861 + ... + 3133911886.

It is an arithmetic number, because the mean of its divisors is an integer number (21937383118).

Almost surely, 2^81481708711 is an apocalyptic number.

81481708711 is a deficient number, since it is larger than the sum of its proper divisors (6267823761).

81481708711 is a wasteful number, since it uses less digits than its factorization.

81481708711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6267823760.

The product of its (nonzero) digits is 100352, while the sum is 46.

The spelling of 81481708711 in words is "eighty-one billion, four hundred eighty-one million, seven hundred eight thousand, seven hundred eleven".