81369047 has 2 divisors, whose sum is σ = 81369048. Its totient is φ = 81369046.

The previous prime is 81369019. The next prime is 81369091. The reversal of 81369047 is 74096318.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81369047 - 2¹⁶ = 81303511 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81369047.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81369097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40684523 + 40684524.

It is an arithmetic number, because the mean of its divisors is an integer number (40684524).

Almost surely, 2^81369047 is an apocalyptic number.

81369047 is a deficient number, since it is larger than the sum of its proper divisors (1).

81369047 is an equidigital number, since it uses as much as digits as its factorization.

81369047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 81369047 is about 9020.4793109901. The cubic root of 81369047 is about 433.3309841424.

The spelling of 81369047 in words is "eighty-one million, three hundred sixty-nine thousand, forty-seven".