81380347311 has 4 divisors (see below), whose sum is σ = 108507129752. Its totient is φ = 54253564872.

The previous prime is 81380347309. The next prime is 81380347357. The reversal of 81380347311 is 11374308318.

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

It is not a de Polignac number, because 81380347311 - 2¹ = 81380347309 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 81380347311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81380347381) 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, 13563391216 + ... + 13563391221.

It is an arithmetic number, because the mean of its divisors is an integer number (27126782438).

Almost surely, 2^81380347311 is an apocalyptic number.

81380347311 is a deficient number, since it is larger than the sum of its proper divisors (27126782441).

81380347311 is a wasteful number, since it uses less digits than its factorization.

81380347311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27126782440.

The product of its (nonzero) digits is 48384, while the sum is 39.

The spelling of 81380347311 in words is "eighty-one billion, three hundred eighty million, three hundred forty-seven thousand, three hundred eleven".