666515216 has 10 divisors (see below), whose sum is σ = 1291373262. Its totient is φ = 333257600.

The previous prime is 666515173. The next prime is 666515233. The reversal of 666515216 is 612515666.

666515216 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 665433616 + 1081600 = 25796^2 + 1040^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 666515216.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20828585 + ... + 20828616.

Almost surely, 2^666515216 is an apocalyptic number.

It is an amenable number.

666515216 is a deficient number, since it is larger than the sum of its proper divisors (624858046).

666515216 is a wasteful number, since it uses less digits than its factorization.

666515216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41657209 (or 41657203 counting only the distinct ones).

The product of its digits is 64800, while the sum is 38.

The square root of 666515216 is about 25816.9559785812. The cubic root of 666515216 is about 873.5143075544.

The spelling of 666515216 in words is "six hundred sixty-six million, five hundred fifteen thousand, two hundred sixteen".