81782887 has 2 divisors, whose sum is σ = 81782888. Its totient is φ = 81782886.

The previous prime is 81782873. The next prime is 81782893. The reversal of 81782887 is 78828718.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81782887 - 2⁷ = 81782759 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 81782887.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81782837) 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, 40891443 + 40891444.

It is an arithmetic number, because the mean of its divisors is an integer number (40891444).

Almost surely, 2^81782887 is an apocalyptic number.

81782887 is a deficient number, since it is larger than the sum of its proper divisors (1).

81782887 is an equidigital number, since it uses as much as digits as its factorization.

81782887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 401408, while the sum is 49.

The square root of 81782887 is about 9043.3891323994. The cubic root of 81782887 is about 434.0643773911.

The spelling of 81782887 in words is "eighty-one million, seven hundred eighty-two thousand, eight hundred eighty-seven".