81859545 has 32 divisors (see below), whose sum is σ = 146889600. Its totient is φ = 43250112.

The previous prime is 81859537. The next prime is 81859549. The reversal of 81859545 is 54595818.

It is a happy number.

81859545 is a `hidden beast` number, since 8 + 18 + 595 + 45 = 666.

It is not a de Polignac number, because 81859545 - 2³ = 81859537 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 81859545.

It is not an unprimeable number, because it can be changed into a prime (81859549) 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 31 ways as a sum of consecutive naturals, for example, 11934 + ... + 17496.

It is an arithmetic number, because the mean of its divisors is an integer number (4590300).

Almost surely, 2^81859545 is an apocalyptic number.

It is an amenable number.

81859545 is a deficient number, since it is larger than the sum of its proper divisors (65030055).

81859545 is a wasteful number, since it uses less digits than its factorization.

81859545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5686 (or 5680 counting only the distinct ones).

The product of its digits is 288000, while the sum is 45.

The square root of 81859545 is about 9047.6264843328. The cubic root of 81859545 is about 434.1999563499.

The spelling of 81859545 in words is "eighty-one million, eight hundred fifty-nine thousand, five hundred forty-five".