81432085 has 16 divisors (see below), whose sum is σ = 111891456. Its totient is φ = 55732608.

The previous prime is 81432083. The next prime is 81432103. The reversal of 81432085 is 58023418.

It is a cyclic number.

It is not a de Polignac number, because 81432085 - 2¹ = 81432083 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81432083) 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 in 15 ways as a sum of consecutive naturals, for example, 19329 + ... + 23161.

It is an arithmetic number, because the mean of its divisors is an integer number (6993216).

Almost surely, 2^81432085 is an apocalyptic number.

It is an amenable number.

81432085 is a deficient number, since it is larger than the sum of its proper divisors (30459371).

81432085 is a wasteful number, since it uses less digits than its factorization.

81432085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4452.

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 81432085 is about 9023.9727947285. The cubic root of 81432085 is about 433.4428582456.

The spelling of 81432085 in words is "eighty-one million, four hundred thirty-two thousand, eighty-five".