201216666 has 32 divisors (see below), whose sum is σ = 460500480. Its totient is φ = 57418416.

The previous prime is 201216623. The next prime is 201216667. The reversal of 201216666 is 666612102.

It is not an unprimeable number, because it can be changed into a prime (201216667) 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 15 ways as a sum of consecutive naturals, for example, 37245 + ... + 42303.

It is an arithmetic number, because the mean of its divisors is an integer number (14390640).

Almost surely, 2^201216666 is an apocalyptic number.

201216666 is an abundant number, since it is smaller than the sum of its proper divisors (259283814).

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

201216666 is a wasteful number, since it uses less digits than its factorization.

201216666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6018.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 201216666 is about 14185.0860413323. The cubic root of 201216666 is about 585.9870020841.

Adding to 201216666 its reverse (666612102), we get a palindrome (867828768).

The spelling of 201216666 in words is "two hundred one million, two hundred sixteen thousand, six hundred sixty-six".