81812211347 has 2 divisors, whose sum is σ = 81812211348. Its totient is φ = 81812211346.

The previous prime is 81812211311. The next prime is 81812211521. The reversal of 81812211347 is 74311221818.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81812211347 - 2³⁰ = 80738469523 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81812211347.

It is not a weakly prime, because it can be changed into another prime (81812201347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40906105673 + 40906105674.

It is an arithmetic number, because the mean of its divisors is an integer number (40906105674).

Almost surely, 2^81812211347 is an apocalyptic number.

81812211347 is a deficient number, since it is larger than the sum of its proper divisors (1).

81812211347 is an equidigital number, since it uses as much as digits as its factorization.

81812211347 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21504, while the sum is 38.

The spelling of 81812211347 in words is "eighty-one billion, eight hundred twelve million, two hundred eleven thousand, three hundred forty-seven".