81075473 has 4 divisors (see below), whose sum is σ = 83266740. Its totient is φ = 78884208.

The previous prime is 81075469. The next prime is 81075487. The reversal of 81075473 is 37457018.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 62995969 + 18079504 = 7937^2 + 4252^2 .

It is a cyclic number.

It is not a de Polignac number, because 81075473 - 2² = 81075469 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (81075443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1095578 + ... + 1095651.

It is an arithmetic number, because the mean of its divisors is an integer number (20816685).

Almost surely, 2^81075473 is an apocalyptic number.

It is an amenable number.

81075473 is a deficient number, since it is larger than the sum of its proper divisors (2191267).

81075473 is a wasteful number, since it uses less digits than its factorization.

81075473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2191266.

The product of its (nonzero) digits is 23520, while the sum is 35.

The square root of 81075473 is about 9004.1919681890. The cubic root of 81075473 is about 432.8092132052.

The spelling of 81075473 in words is "eighty-one million, seventy-five thousand, four hundred seventy-three".