666728528 has 10 divisors (see below), whose sum is σ = 1291786554. Its totient is φ = 333364256.

The previous prime is 666728527. The next prime is 666728581. The reversal of 666728528 is 825827666.

It can be written as a sum of positive squares in only one way, i.e., 579268624 + 87459904 = 24068^2 + 9352^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666728521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20835251 + ... + 20835282.

Almost surely, 2^666728528 is an apocalyptic number.

It is an amenable number.

666728528 is a deficient number, since it is larger than the sum of its proper divisors (625058026).

666728528 is a wasteful number, since it uses less digits than its factorization.

666728528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41670541 (or 41670535 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 50.

The square root of 666728528 is about 25821.0868864965. The cubic root of 666728528 is about 873.6074843267.

The spelling of 666728528 in words is "six hundred sixty-six million, seven hundred twenty-eight thousand, five hundred twenty-eight".