81079384691 has 2 divisors, whose sum is σ = 81079384692. Its totient is φ = 81079384690.

The previous prime is 81079384669. The next prime is 81079384717. The reversal of 81079384691 is 19648397018.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81079384691 - 2¹⁸ = 81079122547 is a prime.

It is not a weakly prime, because it can be changed into another prime (81079384291) 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, 40539692345 + 40539692346.

It is an arithmetic number, because the mean of its divisors is an integer number (40539692346).

Almost surely, 2^81079384691 is an apocalyptic number.

81079384691 is a deficient number, since it is larger than the sum of its proper divisors (1).

81079384691 is an equidigital number, since it uses as much as digits as its factorization.

81079384691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2612736, while the sum is 56.

The spelling of 81079384691 in words is "eighty-one billion, seventy-nine million, three hundred eighty-four thousand, six hundred ninety-one".