66678224 has 10 divisors (see below), whose sum is σ = 129189090. Its totient is φ = 33339104.

The previous prime is 66678217. The next prime is 66678229. The reversal of 66678224 is 42287666.

It can be written as a sum of positive squares in only one way, i.e., 33408400 + 33269824 = 5780^2 + 5768^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66678229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2083679 + ... + 2083710.

It is an arithmetic number, because the mean of its divisors is an integer number (12918909).

Almost surely, 2^66678224 is an apocalyptic number.

It is an amenable number.

66678224 is a deficient number, since it is larger than the sum of its proper divisors (62510866).

66678224 is a wasteful number, since it uses less digits than its factorization.

66678224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4167397 (or 4167391 counting only the distinct ones).

The product of its digits is 193536, while the sum is 41.

The square root of 66678224 is about 8165.6735178428. The cubic root of 66678224 is about 405.5035630296.

The spelling of 66678224 in words is "sixty-six million, six hundred seventy-eight thousand, two hundred twenty-four".