81966455287 has 2 divisors, whose sum is σ = 81966455288. Its totient is φ = 81966455286.

The previous prime is 81966455279. The next prime is 81966455339. The reversal of 81966455287 is 78255466918.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81966455287 - 2³ = 81966455279 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81966425287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40983227643 + 40983227644.

It is an arithmetic number, because the mean of its divisors is an integer number (40983227644).

Almost surely, 2^81966455287 is an apocalyptic number.

81966455287 is a deficient number, since it is larger than the sum of its proper divisors (1).

81966455287 is an equidigital number, since it uses as much as digits as its factorization.

81966455287 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29030400, while the sum is 61.

The spelling of 81966455287 in words is "eighty-one billion, nine hundred sixty-six million, four hundred fifty-five thousand, two hundred eighty-seven".