81083645 has 6 divisors (see below), whose sum is σ = 97324542. Its totient is φ = 64850808.

The previous prime is 81083627. The next prime is 81083647. The reversal of 81083645 is 54638018.

It can be written as a sum of positive squares in only one way, i.e., 64866916 + 16216729 = 8054^2 + 4027^2 .

It is not a de Polignac number, because 81083645 - 2¹² = 81079549 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 (81083647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18122 + ... + 22148.

It is an arithmetic number, because the mean of its divisors is an integer number (16220757).

Almost surely, 2^81083645 is an apocalyptic number.

It is an amenable number.

81083645 is a deficient number, since it is larger than the sum of its proper divisors (16240897).

81083645 is an frugal number, since it uses more digits than its factorization.

81083645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8059 (or 4032 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 35.

The square root of 81083645 is about 9004.6457453917. The cubic root of 81083645 is about 432.8237543807.

The spelling of 81083645 in words is "eighty-one million, eighty-three thousand, six hundred forty-five".