666728223 has 16 divisors (see below), whose sum is σ = 1016365056. Its totient is φ = 380838240.

The previous prime is 666728203. The next prime is 666728273. The reversal of 666728223 is 322827666.

It is not a de Polignac number, because 666728223 - 2¹⁴ = 666711839 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666728203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70813 + ... + 79673.

It is an arithmetic number, because the mean of its divisors is an integer number (63522816).

Almost surely, 2^666728223 is an apocalyptic number.

666728223 is a deficient number, since it is larger than the sum of its proper divisors (349636833).

666728223 is a wasteful number, since it uses less digits than its factorization.

666728223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12454.

The product of its digits is 290304, while the sum is 42.

The square root of 666728223 is about 25821.0809804702. The cubic root of 666728223 is about 873.6073511139.

The spelling of 666728223 in words is "six hundred sixty-six million, seven hundred twenty-eight thousand, two hundred twenty-three".