81545105 has 16 divisors (see below), whose sum is σ = 101899728. Its totient is φ = 62592000.

The previous prime is 81545099. The next prime is 81545137. The reversal of 81545105 is 50154518.

It can be written as a sum of positive squares in 8 ways, for example, as 12306064 + 69239041 = 3508^2 + 8321^2 .

It is not a de Polignac number, because 81545105 - 2⁶ = 81545041 is a prime.

It is a super-2 number, since 2×81545105² = 13299208298922050, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

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, 9245 + ... + 15765.

It is an arithmetic number, because the mean of its divisors is an integer number (6368733).

Almost surely, 2^81545105 is an apocalyptic number.

It is an amenable number.

81545105 is a deficient number, since it is larger than the sum of its proper divisors (20354623).

81545105 is a wasteful number, since it uses less digits than its factorization.

81545105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6628.

The product of its (nonzero) digits is 4000, while the sum is 29.

The square root of 81545105 is about 9030.2328319928. The cubic root of 81545105 is about 433.6432913872.

The spelling of 81545105 in words is "eighty-one million, five hundred forty-five thousand, one hundred five".