81969159847 has 2 divisors, whose sum is σ = 81969159848. Its totient is φ = 81969159846.

The previous prime is 81969159829. The next prime is 81969159851. The reversal of 81969159847 is 74895196918.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81969159847 - 2¹⁹ = 81968635559 is a prime.

It is a super-3 number, since 3×81969159847³ (a number of 34 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81969159817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40984579923 + 40984579924.

It is an arithmetic number, because the mean of its divisors is an integer number (40984579924).

Almost surely, 2^81969159847 is an apocalyptic number.

81969159847 is a deficient number, since it is larger than the sum of its proper divisors (1).

81969159847 is an equidigital number, since it uses as much as digits as its factorization.

81969159847 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 39191040, while the sum is 67.

The spelling of 81969159847 in words is "eighty-one billion, nine hundred sixty-nine million, one hundred fifty-nine thousand, eight hundred forty-seven".