81826408517 has 32 divisors (see below), whose sum is σ = 96888545280. Its totient is φ = 67665911040.

The previous prime is 81826408511. The next prime is 81826408529. The reversal of 81826408517 is 71580462818.

It is not a de Polignac number, because 81826408517 - 2¹² = 81826404421 is a prime.

It is a super-2 number, since 2×81826408517² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81826408511) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4427498 + ... + 4445940.

It is an arithmetic number, because the mean of its divisors is an integer number (3027767040).

Almost surely, 2^81826408517 is an apocalyptic number.

It is an amenable number.

81826408517 is a deficient number, since it is larger than the sum of its proper divisors (15062136763).

81826408517 is a wasteful number, since it uses less digits than its factorization.

81826408517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18713.

The product of its (nonzero) digits is 860160, while the sum is 50.

The spelling of 81826408517 in words is "eighty-one billion, eight hundred twenty-six million, four hundred eight thousand, five hundred seventeen".