66478571 has 4 divisors (see below), whose sum is σ = 66494952. Its totient is φ = 66462192.

The previous prime is 66478553. The next prime is 66478597. The reversal of 66478571 is 17587466.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 66478571 - 2¹⁸ = 66216427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66478771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2936 + ... + 11898.

It is an arithmetic number, because the mean of its divisors is an integer number (16623738).

Almost surely, 2^66478571 is an apocalyptic number.

66478571 is a deficient number, since it is larger than the sum of its proper divisors (16381).

66478571 is an equidigital number, since it uses as much as digits as its factorization.

66478571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16380.

The product of its digits is 282240, while the sum is 44.

The square root of 66478571 is about 8153.4392129947. The cubic root of 66478571 is about 405.0984285483.

The spelling of 66478571 in words is "sixty-six million, four hundred seventy-eight thousand, five hundred seventy-one".