81586469 has 2 divisors, whose sum is σ = 81586470. Its totient is φ = 81586468.

The previous prime is 81586457. The next prime is 81586471. The reversal of 81586469 is 96468518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41770369 + 39816100 = 6463^2 + 6310^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81586469 is a prime.

It is a super-2 number, since 2×81586469² = 13312703847775922, which contains 22 as substring.

Together with 81586471, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81586429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40793234 + 40793235.

It is an arithmetic number, because the mean of its divisors is an integer number (40793235).

Almost surely, 2^81586469 is an apocalyptic number.

It is an amenable number.

81586469 is a deficient number, since it is larger than the sum of its proper divisors (1).

81586469 is an equidigital number, since it uses as much as digits as its factorization.

81586469 is an evil number, because the sum of its binary digits is even.

The product of its digits is 414720, while the sum is 47.

The square root of 81586469 is about 9032.5228480198. The cubic root of 81586469 is about 433.7166012813.

The spelling of 81586469 in words is "eighty-one million, five hundred eighty-six thousand, four hundred sixty-nine".