81105529 has 4 divisors (see below), whose sum is σ = 82635876. Its totient is φ = 79575184.

The previous prime is 81105523. The next prime is 81105559. The reversal of 81105529 is 92550118.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 92550118 = 2 ⋅46275059.

It can be written as a sum of positive squares in 2 ways, for example, as 33177600 + 47927929 = 5760^2 + 6923^2 .

It is a cyclic number.

It is not a de Polignac number, because 81105529 - 2¹³ = 81097337 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81105529.

It is not an unprimeable number, because it can be changed into a prime (81105523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 765094 + ... + 765199.

It is an arithmetic number, because the mean of its divisors is an integer number (20658969).

Almost surely, 2^81105529 is an apocalyptic number.

It is an amenable number.

81105529 is a deficient number, since it is larger than the sum of its proper divisors (1530347).

81105529 is a wasteful number, since it uses less digits than its factorization.

81105529 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1530346.

The product of its (nonzero) digits is 3600, while the sum is 31.

The square root of 81105529 is about 9005.8608139367. The cubic root of 81105529 is about 432.8626897420.

The spelling of 81105529 in words is "eighty-one million, one hundred five thousand, five hundred twenty-nine".