66628456 has 8 divisors (see below), whose sum is σ = 124928370. Its totient is φ = 33314224.

The previous prime is 66628451. The next prime is 66628481. The reversal of 66628456 is 65482666.

It can be written as a sum of positive squares in only one way, i.e., 61936900 + 4691556 = 7870^2 + 2166^2 .

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

It is a super-2 number, since 2×66628456² = 8878702297887872, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66628451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4164271 + ... + 4164286.

Almost surely, 2^66628456 is an apocalyptic number.

It is an amenable number.

66628456 is a deficient number, since it is larger than the sum of its proper divisors (58299914).

66628456 is a wasteful number, since it uses less digits than its factorization.

66628456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8328563 (or 8328559 counting only the distinct ones).

The product of its digits is 414720, while the sum is 43.

The square root of 66628456 is about 8162.6255579930. The cubic root of 66628456 is about 405.4026499019.

The spelling of 66628456 in words is "sixty-six million, six hundred twenty-eight thousand, four hundred fifty-six".