66628 has 6 divisors (see below), whose sum is σ = 116606. Its totient is φ = 33312.

The previous prime is 66617. The next prime is 66629. The reversal of 66628 is 82666.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 66564 + 64 = 258^2 + 8^2 .

It is a junction number, because it is equal to n+sod(n) for n = 66596 and 66605.

It is not an unprimeable number, because it can be changed into a prime (66629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8325 + ... + 8332.

2⁶⁶⁶²⁸ is an apocalyptic number.

It is an amenable number.

66628 is a deficient number, since it is larger than the sum of its proper divisors (49978).

66628 is a wasteful number, since it uses less digits than its factorization.

66628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16661 (or 16659 counting only the distinct ones).

The product of its digits is 3456, while the sum is 28.

The square root of 66628 is about 258.1240012087. The cubic root of 66628 is about 40.5401725052.

It can be divided in two parts, 6662 and 8, that added together give a triangular number (6670 = T₁₁₅).

The spelling of 66628 in words is "sixty-six thousand, six hundred twenty-eight".