81586559 has 2 divisors, whose sum is σ = 81586560. Its totient is φ = 81586558.

The previous prime is 81586529. The next prime is 81586573. The reversal of 81586559 is 95568518.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81586559 - 2¹² = 81582463 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81586529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40793279 + 40793280.

It is an arithmetic number, because the mean of its divisors is an integer number (40793280).

Almost surely, 2^81586559 is an apocalyptic number.

81586559 is a deficient number, since it is larger than the sum of its proper divisors (1).

81586559 is an equidigital number, since it uses as much as digits as its factorization.

81586559 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432000, while the sum is 47.

The square root of 81586559 is about 9032.5278300152. The cubic root of 81586559 is about 433.7167607624.

The spelling of 81586559 in words is "eighty-one million, five hundred eighty-six thousand, five hundred fifty-nine".