66543172 has 6 divisors (see below), whose sum is σ = 116450558. Its totient is φ = 33271584.

The previous prime is 66543167. The next prime is 66543173. The reversal of 66543172 is 27134566.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 62948356 + 3594816 = 7934^2 + 1896^2 .

It is not an unprimeable number, because it can be changed into a prime (66543173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8317893 + ... + 8317900.

Almost surely, 2^66543172 is an apocalyptic number.

It is an amenable number.

66543172 is a deficient number, since it is larger than the sum of its proper divisors (49907386).

66543172 is a wasteful number, since it uses less digits than its factorization.

66543172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16635797 (or 16635795 counting only the distinct ones).

The product of its digits is 30240, while the sum is 34.

The square root of 66543172 is about 8157.3998308284. The cubic root of 66543172 is about 405.2296051108.

The spelling of 66543172 in words is "sixty-six million, five hundred forty-three thousand, one hundred seventy-two".