81079384669 has 2 divisors, whose sum is σ = 81079384670. Its totient is φ = 81079384668.

The previous prime is 81079384657. The next prime is 81079384691. The reversal of 81079384669 is 96648397018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62457507225 + 18621877444 = 249915^2 + 136462^2 .

It is a cyclic number.

It is not a de Polignac number, because 81079384669 - 2²⁵ = 81045830237 is a prime.

It is a super-2 number, since 2×81079384669² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81079384609) 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, 40539692334 + 40539692335.

It is an arithmetic number, because the mean of its divisors is an integer number (40539692335).

Almost surely, 2^81079384669 is an apocalyptic number.

It is an amenable number.

81079384669 is a deficient number, since it is larger than the sum of its proper divisors (1).

81079384669 is an equidigital number, since it uses as much as digits as its factorization.

81079384669 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15676416, while the sum is 61.

The spelling of 81079384669 in words is "eighty-one billion, seventy-nine million, three hundred eighty-four thousand, six hundred sixty-nine".