666216052 has 24 divisors (see below), whose sum is σ = 1195515720. Its totient is φ = 324656640.

The previous prime is 666216037. The next prime is 666216059. The reversal of 666216052 is 250612666.

It can be written as a sum of positive squares in 4 ways, for example, as 8088336 + 658127716 = 2844^2 + 25654^2 .

It is a junction number, because it is equal to n+sod(n) for n = 666215999 and 666216017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666216059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 279088 + ... + 281464.

It is an arithmetic number, because the mean of its divisors is an integer number (49813155).

Almost surely, 2^666216052 is an apocalyptic number.

It is an amenable number.

666216052 is a deficient number, since it is larger than the sum of its proper divisors (529299668).

666216052 is a wasteful number, since it uses less digits than its factorization.

666216052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4131 (or 4129 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 666216052 is about 25811.1613841764. The cubic root of 666216052 is about 873.3835962888.

The spelling of 666216052 in words is "six hundred sixty-six million, two hundred sixteen thousand, fifty-two".