81766797823 has 2 divisors, whose sum is σ = 81766797824. Its totient is φ = 81766797822.

The previous prime is 81766797821. The next prime is 81766797857. The reversal of 81766797823 is 32879766718.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81766797823 - 2¹ = 81766797821 is a prime.

Together with 81766797821, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81766797821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40883398911 + 40883398912.

It is an arithmetic number, because the mean of its divisors is an integer number (40883398912).

Almost surely, 2^81766797823 is an apocalyptic number.

81766797823 is a deficient number, since it is larger than the sum of its proper divisors (1).

81766797823 is an equidigital number, since it uses as much as digits as its factorization.

81766797823 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42674688, while the sum is 64.

The spelling of 81766797823 in words is "eighty-one billion, seven hundred sixty-six million, seven hundred ninety-seven thousand, eight hundred twenty-three".