81116587 has 2 divisors, whose sum is σ = 81116588. Its totient is φ = 81116586.

The previous prime is 81116557. The next prime is 81116591. The reversal of 81116587 is 78561118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81116587 - 2⁷ = 81116459 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81116507) 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, 40558293 + 40558294.

It is an arithmetic number, because the mean of its divisors is an integer number (40558294).

Almost surely, 2^81116587 is an apocalyptic number.

81116587 is a deficient number, since it is larger than the sum of its proper divisors (1).

81116587 is an equidigital number, since it uses as much as digits as its factorization.

81116587 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13440, while the sum is 37.

The square root of 81116587 is about 9006.4747265509. The cubic root of 81116587 is about 432.8823611428.

The spelling of 81116587 in words is "eighty-one million, one hundred sixteen thousand, five hundred eighty-seven".