81640462327 has 2 divisors, whose sum is σ = 81640462328. Its totient is φ = 81640462326.

The previous prime is 81640462289. The next prime is 81640462381. The reversal of 81640462327 is 72326404618.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81640462327 - 2³¹ = 79492978679 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81640462027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40820231163 + 40820231164.

It is an arithmetic number, because the mean of its divisors is an integer number (40820231164).

Almost surely, 2^81640462327 is an apocalyptic number.

81640462327 is a deficient number, since it is larger than the sum of its proper divisors (1).

81640462327 is an equidigital number, since it uses as much as digits as its factorization.

81640462327 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 387072, while the sum is 43.

The spelling of 81640462327 in words is "eighty-one billion, six hundred forty million, four hundred sixty-two thousand, three hundred twenty-seven".