81716859461 has 8 divisors (see below), whose sum is σ = 83274951960. Its totient is φ = 80159369472.

The previous prime is 81716859457. The next prime is 81716859491. The reversal of 81716859461 is 16495861718.

It can be written as a sum of positive squares in 4 ways, for example, as 16778020900 + 64938838561 = 129530^2 + 254831^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 81716859461 - 2² = 81716859457 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81716859397 and 81716859406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81716859491) 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, 128081 + ... + 424073.

It is an arithmetic number, because the mean of its divisors is an integer number (10409368995).

Almost surely, 2^81716859461 is an apocalyptic number.

It is an amenable number.

81716859461 is a deficient number, since it is larger than the sum of its proper divisors (1558092499).

81716859461 is a wasteful number, since it uses less digits than its factorization.

81716859461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301255.

The product of its digits is 2903040, while the sum is 56.

The spelling of 81716859461 in words is "eighty-one billion, seven hundred sixteen million, eight hundred fifty-nine thousand, four hundred sixty-one".