666728214 has 32 divisors (see below), whose sum is σ = 1346997600. Its totient is φ = 219996672.

The previous prime is 666728203. The next prime is 666728273. The reversal of 666728214 is 412827666.

It is a super-2 number, since 2×666728214² = 889053022687259592, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 300172 + ... + 302384.

It is an arithmetic number, because the mean of its divisors is an integer number (42093675).

Almost surely, 2^666728214 is an apocalyptic number.

666728214 is an abundant number, since it is smaller than the sum of its proper divisors (680269386).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666728214 is a wasteful number, since it uses less digits than its factorization.

666728214 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2704.

The product of its digits is 193536, while the sum is 42.

The square root of 666728214 is about 25821.0808061940. The cubic root of 666728214 is about 873.6073471831.

The spelling of 666728214 in words is "six hundred sixty-six million, seven hundred twenty-eight thousand, two hundred fourteen".