81235199 has 2 divisors, whose sum is σ = 81235200. Its totient is φ = 81235198.

The previous prime is 81235181. The next prime is 81235207. The reversal of 81235199 is 99153218.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81235199 - 2¹² = 81231103 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81235139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40617599 + 40617600.

It is an arithmetic number, because the mean of its divisors is an integer number (40617600).

Almost surely, 2^81235199 is an apocalyptic number.

81235199 is a deficient number, since it is larger than the sum of its proper divisors (1).

81235199 is an equidigital number, since it uses as much as digits as its factorization.

81235199 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19440, while the sum is 38.

The square root of 81235199 is about 9013.0571395060. The cubic root of 81235199 is about 433.0932511656.

The spelling of 81235199 in words is "eighty-one million, two hundred thirty-five thousand, one hundred ninety-nine".