81215066367671 has 2 divisors, whose sum is σ = 81215066367672. Its totient is φ = 81215066367670.

The previous prime is 81215066367667. The next prime is 81215066367683. The reversal of 81215066367671 is 17676366051218.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81215066367671 - 2² = 81215066367667 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81215066367671.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81215066360671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40607533183835 + 40607533183836.

It is an arithmetic number, because the mean of its divisors is an integer number (40607533183836).

Almost surely, 2^{81215066367671} is an apocalyptic number.

81215066367671 is a deficient number, since it is larger than the sum of its proper divisors (1).

81215066367671 is an equidigital number, since it uses as much as digits as its factorization.

81215066367671 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15240960, while the sum is 59.

The spelling of 81215066367671 in words is "eighty-one trillion, two hundred fifteen billion, sixty-six million, three hundred sixty-seven thousand, six hundred seventy-one".