81130719941 has 4 divisors (see below), whose sum is σ = 81131379084. Its totient is φ = 81130060800.

The previous prime is 81130719919. The next prime is 81130719959. The reversal of 81130719941 is 14991703118.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 17490062500 + 63640657441 = 132250^2 + 252271^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81130719941 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81130719892 and 81130719901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81130719911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83900 + ... + 411461.

It is an arithmetic number, because the mean of its divisors is an integer number (20282844771).

Almost surely, 2^81130719941 is an apocalyptic number.

It is an amenable number.

81130719941 is a deficient number, since it is larger than the sum of its proper divisors (659143).

81130719941 is a wasteful number, since it uses less digits than its factorization.

81130719941 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 659142.

The product of its (nonzero) digits is 54432, while the sum is 44.

The spelling of 81130719941 in words is "eighty-one billion, one hundred thirty million, seven hundred nineteen thousand, nine hundred forty-one".