81699876079 has 2 divisors, whose sum is σ = 81699876080. Its totient is φ = 81699876078.

The previous prime is 81699876061. The next prime is 81699876197. The reversal of 81699876079 is 97067899618.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81699876079 - 2⁵ = 81699876047 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81699875999 and 81699876017.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81699870079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40849938039 + 40849938040.

It is an arithmetic number, because the mean of its divisors is an integer number (40849938040).

Almost surely, 2^81699876079 is an apocalyptic number.

81699876079 is a deficient number, since it is larger than the sum of its proper divisors (1).

81699876079 is an equidigital number, since it uses as much as digits as its factorization.

81699876079 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 82301184, while the sum is 70.

The spelling of 81699876079 in words is "eighty-one billion, six hundred ninety-nine million, eight hundred seventy-six thousand, seventy-nine".