81589229 has 2 divisors, whose sum is σ = 81589230. Its totient is φ = 81589228.

The previous prime is 81589223. The next prime is 81589231. The reversal of 81589229 is 92298518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80820100 + 769129 = 8990^2 + 877^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81589229 is a prime.

Together with 81589231, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81589229.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81589223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40794614 + 40794615.

It is an arithmetic number, because the mean of its divisors is an integer number (40794615).

Almost surely, 2^81589229 is an apocalyptic number.

It is an amenable number.

81589229 is a deficient number, since it is larger than the sum of its proper divisors (1).

81589229 is an equidigital number, since it uses as much as digits as its factorization.

81589229 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 44.

The square root of 81589229 is about 9032.6756279632. The cubic root of 81589229 is about 433.7214919793.

It can be divided in two parts, 81589 and 229, that added together give a palindrome (81818).

The spelling of 81589229 in words is "eighty-one million, five hundred eighty-nine thousand, two hundred twenty-nine".