81045589 has 2 divisors, whose sum is σ = 81045590. Its totient is φ = 81045588.

The previous prime is 81045581. The next prime is 81045631. The reversal of 81045589 is 98554018.

81045589 is nontrivially palindromic in base 6.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75082225 + 5963364 = 8665^2 + 2442^2 .

It is a cyclic number.

It is not a de Polignac number, because 81045589 - 2³ = 81045581 is a prime.

It is equal to p_4726966 and since 81045589 and 4726966 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81045581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40522794 + 40522795.

It is an arithmetic number, because the mean of its divisors is an integer number (40522795).

Almost surely, 2^81045589 is an apocalyptic number.

It is an amenable number.

81045589 is a deficient number, since it is larger than the sum of its proper divisors (1).

81045589 is an equidigital number, since it uses as much as digits as its factorization.

81045589 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 57600, while the sum is 40.

The square root of 81045589 is about 9002.5323659513. The cubic root of 81045589 is about 432.7560295911.

The spelling of 81045589 in words is "eighty-one million, forty-five thousand, five hundred eighty-nine".