81003573 has 24 divisors (see below), whose sum is σ = 134267328. Its totient is φ = 46098432.

The previous prime is 81003563. The next prime is 81003581. The reversal of 81003573 is 37530018.

It is not a de Polignac number, because 81003573 - 2⁶ = 81003509 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81003523) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13690 + ... + 18692.

It is an arithmetic number, because the mean of its divisors is an integer number (5594472).

Almost surely, 2^81003573 is an apocalyptic number.

It is an amenable number.

81003573 is a deficient number, since it is larger than the sum of its proper divisors (53263755).

81003573 is a wasteful number, since it uses less digits than its factorization.

81003573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5273 (or 5270 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 81003573 is about 9000.1984978110. The cubic root of 81003573 is about 432.6812329218.

The spelling of 81003573 in words is "eighty-one million, three thousand, five hundred seventy-three".