81238163 has 2 divisors, whose sum is σ = 81238164. Its totient is φ = 81238162.

The previous prime is 81238147. The next prime is 81238229. The reversal of 81238163 is 36183218.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81238163 - 2⁴ = 81238147 is a prime.

It is a super-2 number, since 2×81238163² = 13199278255229138, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (81238363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40619081 + 40619082.

It is an arithmetic number, because the mean of its divisors is an integer number (40619082).

Almost surely, 2^81238163 is an apocalyptic number.

81238163 is a deficient number, since it is larger than the sum of its proper divisors (1).

81238163 is an equidigital number, since it uses as much as digits as its factorization.

81238163 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 32.

The square root of 81238163 is about 9013.2215661216. The cubic root of 81238163 is about 433.0985184750.

The spelling of 81238163 in words is "eighty-one million, two hundred thirty-eight thousand, one hundred sixty-three".