81009573 has 8 divisors (see below), whose sum is σ = 114366528. Its totient is φ = 50829504.

The previous prime is 81009571. The next prime is 81009581. The reversal of 81009573 is 37590018.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81009573 - 2¹ = 81009571 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81009571) 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 7 ways as a sum of consecutive naturals, for example, 794161 + ... + 794262.

It is an arithmetic number, because the mean of its divisors is an integer number (14295816).

Almost surely, 2^81009573 is an apocalyptic number.

It is an amenable number.

81009573 is a deficient number, since it is larger than the sum of its proper divisors (33356955).

81009573 is a wasteful number, since it uses less digits than its factorization.

81009573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1588443.

The product of its (nonzero) digits is 7560, while the sum is 33.

The square root of 81009573 is about 9000.5318176206. The cubic root of 81009573 is about 432.6919156740.

The spelling of 81009573 in words is "eighty-one million, nine thousand, five hundred seventy-three".