81844823747 has 2 divisors, whose sum is σ = 81844823748. Its totient is φ = 81844823746.

The previous prime is 81844823743. The next prime is 81844823779. The reversal of 81844823747 is 74732844818.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81844823747 - 2² = 81844823743 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81844823692 and 81844823701.

It is not a weakly prime, because it can be changed into another prime (81844823741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40922411873 + 40922411874.

It is an arithmetic number, because the mean of its divisors is an integer number (40922411874).

Almost surely, 2^81844823747 is an apocalyptic number.

81844823747 is a deficient number, since it is larger than the sum of its proper divisors (1).

81844823747 is an equidigital number, since it uses as much as digits as its factorization.

81844823747 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9633792, while the sum is 56.

The spelling of 81844823747 in words is "eighty-one billion, eight hundred forty-four million, eight hundred twenty-three thousand, seven hundred forty-seven".