71573665 has 16 divisors (see below), whose sum is σ = 90702720. Its totient is φ = 54219312.

The previous prime is 71573647. The next prime is 71573669. The reversal of 71573665 is 56637517.

It is a happy number.

It is not a de Polignac number, because 71573665 - 2¹⁵ = 71540897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (71573669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33252 + ... + 35338.

It is an arithmetic number, because the mean of its divisors is an integer number (5668920).

Almost surely, 2^71573665 is an apocalyptic number.

It is an amenable number.

71573665 is a deficient number, since it is larger than the sum of its proper divisors (19129055).

71573665 is an equidigital number, since it uses as much as digits as its factorization.

71573665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2149 (or 2111 counting only the distinct ones).

The product of its digits is 132300, while the sum is 40.

The square root of 71573665 is about 8460.1220440370. The cubic root of 71573665 is about 415.1940158286.

The spelling of 71573665 in words is "seventy-one million, five hundred seventy-three thousand, six hundred sixty-five".