81145135 has 16 divisors (see below), whose sum is σ = 101210112. Its totient is φ = 62388000.

The previous prime is 81145093. The next prime is 81145139. The reversal of 81145135 is 53154118.

It is not a de Polignac number, because 81145135 - 2¹¹ = 81143087 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 (81145139) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21672 + ... + 25138.

It is an arithmetic number, because the mean of its divisors is an integer number (6325632).

Almost surely, 2^81145135 is an apocalyptic number.

81145135 is a deficient number, since it is larger than the sum of its proper divisors (20064977).

81145135 is a wasteful number, since it uses less digits than its factorization.

81145135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3654.

The product of its digits is 2400, while the sum is 28.

The square root of 81145135 is about 9008.0594469619. The cubic root of 81145135 is about 432.9331377539.

The spelling of 81145135 in words is "eighty-one million, one hundred forty-five thousand, one hundred thirty-five".