81238847 has 2 divisors, whose sum is σ = 81238848. Its totient is φ = 81238846.

The previous prime is 81238841. The next prime is 81238849. The reversal of 81238847 is 74883218.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81238847 - 2¹⁰ = 81237823 is a prime.

Together with 81238849, 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 (81238841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40619423 + 40619424.

It is an arithmetic number, because the mean of its divisors is an integer number (40619424).

Almost surely, 2^81238847 is an apocalyptic number.

81238847 is a deficient number, since it is larger than the sum of its proper divisors (1).

81238847 is an equidigital number, since it uses as much as digits as its factorization.

81238847 is an evil number, because the sum of its binary digits is even.

The product of its digits is 86016, while the sum is 41.

The square root of 81238847 is about 9013.2595102993. The cubic root of 81238847 is about 433.0997339898.

The spelling of 81238847 in words is "eighty-one million, two hundred thirty-eight thousand, eight hundred forty-seven".