66642824 has 8 divisors (see below), whose sum is σ = 124955310. Its totient is φ = 33321408.

The previous prime is 66642817. The next prime is 66642827. The reversal of 66642824 is 42824666.

It can be written as a sum of positive squares in only one way, i.e., 55204900 + 11437924 = 7430^2 + 3382^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (66642827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4165169 + ... + 4165184.

Almost surely, 2^66642824 is an apocalyptic number.

It is an amenable number.

66642824 is a deficient number, since it is larger than the sum of its proper divisors (58312486).

66642824 is a wasteful number, since it uses less digits than its factorization.

66642824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8330359 (or 8330355 counting only the distinct ones).

The product of its digits is 110592, while the sum is 38.

The square root of 66642824 is about 8163.5056195240. The cubic root of 66642824 is about 405.4317886362.

The spelling of 66642824 in words is "sixty-six million, six hundred forty-two thousand, eight hundred twenty-four".