66547971 has 12 divisors (see below), whose sum is σ = 109857072. Its totient is φ = 38027376.

The previous prime is 66547963. The next prime is 66548003. The reversal of 66547971 is 17974566.

It is a happy number.

It is not a de Polignac number, because 66547971 - 2³ = 66547963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66547771) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 528096 + ... + 528221.

It is an arithmetic number, because the mean of its divisors is an integer number (9154756).

Almost surely, 2^66547971 is an apocalyptic number.

66547971 is a deficient number, since it is larger than the sum of its proper divisors (43309101).

66547971 is a wasteful number, since it uses less digits than its factorization.

66547971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1056330 (or 1056327 counting only the distinct ones).

The product of its digits is 317520, while the sum is 45.

The square root of 66547971 is about 8157.6939756282. The cubic root of 66547971 is about 405.2393464064.

The spelling of 66547971 in words is "sixty-six million, five hundred forty-seven thousand, nine hundred seventy-one".