81963960077 has 2 divisors, whose sum is σ = 81963960078. Its totient is φ = 81963960076.

The previous prime is 81963960061. The next prime is 81963960161. The reversal of 81963960077 is 77006936918.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81103065796 + 860894281 = 284786^2 + 29341^2 .

It is a cyclic number.

It is not a de Polignac number, because 81963960077 - 2⁴ = 81963960061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81963960007) 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, 40981980038 + 40981980039.

It is an arithmetic number, because the mean of its divisors is an integer number (40981980039).

Almost surely, 2^81963960077 is an apocalyptic number.

It is an amenable number.

81963960077 is a deficient number, since it is larger than the sum of its proper divisors (1).

81963960077 is an equidigital number, since it uses as much as digits as its factorization.

81963960077 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3429216, while the sum is 56.

The spelling of 81963960077 in words is "eighty-one billion, nine hundred sixty-three million, nine hundred sixty thousand, seventy-seven".