81419776469 has 2 divisors, whose sum is σ = 81419776470. Its totient is φ = 81419776468.

The previous prime is 81419776411. The next prime is 81419776553. The reversal of 81419776469 is 96467791418.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81417774244 + 2002225 = 285338^2 + 1415^2 .

It is a cyclic number.

It is not a de Polignac number, because 81419776469 - 2³² = 77124809173 is a prime.

It is a super-2 number, since 2×81419776469² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81419776409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40709888234 + 40709888235.

It is an arithmetic number, because the mean of its divisors is an integer number (40709888235).

Almost surely, 2^81419776469 is an apocalyptic number.

It is an amenable number.

81419776469 is a deficient number, since it is larger than the sum of its proper divisors (1).

81419776469 is an equidigital number, since it uses as much as digits as its factorization.

81419776469 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18289152, while the sum is 62.

The spelling of 81419776469 in words is "eighty-one billion, four hundred nineteen million, seven hundred seventy-six thousand, four hundred sixty-nine".