81948194711 has 4 divisors (see below), whose sum is σ = 82123673112. Its totient is φ = 81772716312.

The previous prime is 81948194639. The next prime is 81948194749. The reversal of 81948194711 is 11749184918.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81948194711 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 (81948194771) 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, 87738500 + ... + 87739433.

It is an arithmetic number, because the mean of its divisors is an integer number (20530918278).

Almost surely, 2^81948194711 is an apocalyptic number.

81948194711 is a deficient number, since it is larger than the sum of its proper divisors (175478401).

81948194711 is a wasteful number, since it uses less digits than its factorization.

81948194711 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175478400.

The product of its digits is 580608, while the sum is 53.

The spelling of 81948194711 in words is "eighty-one billion, nine hundred forty-eight million, one hundred ninety-four thousand, seven hundred eleven".