81888229 has 2 divisors, whose sum is σ = 81888230. Its totient is φ = 81888228.

The previous prime is 81888223. The next prime is 81888239. The reversal of 81888229 is 92288818.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53319204 + 28569025 = 7302^2 + 5345^2 .

It is a cyclic number.

It is not a de Polignac number, because 81888229 - 2³ = 81888221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81888221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40944114 + 40944115.

It is an arithmetic number, because the mean of its divisors is an integer number (40944115).

Almost surely, 2^81888229 is an apocalyptic number.

It is an amenable number.

81888229 is a deficient number, since it is larger than the sum of its proper divisors (1).

81888229 is an equidigital number, since it uses as much as digits as its factorization.

81888229 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 147456, while the sum is 46.

The square root of 81888229 is about 9049.2115126126. The cubic root of 81888229 is about 434.2506657169.

The spelling of 81888229 in words is "eighty-one million, eight hundred eighty-eight thousand, two hundred twenty-nine".