66461571 has 24 divisors (see below), whose sum is σ = 105334320. Its totient is φ = 40046400.

The previous prime is 66461557. The next prime is 66461581. The reversal of 66461571 is 17516466.

66461571 is a `hidden beast` number, since 6 + 646 + 1 + 5 + 7 + 1 = 666.

It is not a de Polignac number, because 66461571 - 2¹⁴ = 66445187 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66461581) 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, 16065 + ... + 19773.

It is an arithmetic number, because the mean of its divisors is an integer number (4388930).

Almost surely, 2^66461571 is an apocalyptic number.

66461571 is a deficient number, since it is larger than the sum of its proper divisors (38872749).

66461571 is a wasteful number, since it uses less digits than its factorization.

66461571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3907 (or 3904 counting only the distinct ones).

The product of its digits is 30240, while the sum is 36.

The square root of 66461571 is about 8152.3966414791. The cubic root of 66461571 is about 405.0638948117.

The spelling of 66461571 in words is "sixty-six million, four hundred sixty-one thousand, five hundred seventy-one".