20216666 has 8 divisors (see below), whose sum is σ = 30603540. Its totient is φ = 10015488.

The previous prime is 20216659. The next prime is 20216699. The reversal of 20216666 is 66661202.

It can be written as a sum of positive squares in 2 ways, for example, as 19616041 + 600625 = 4429^2 + 775^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46151 + ... + 46586.

Almost surely, 2^20216666 is an apocalyptic number.

20216666 is a deficient number, since it is larger than the sum of its proper divisors (10386874).

20216666 is a wasteful number, since it uses less digits than its factorization.

20216666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92848.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 20216666 is about 4496.2946967475. The cubic root of 20216666 is about 272.4184465432.

Adding to 20216666 its reverse (66661202), we get a palindrome (86877868).

The spelling of 20216666 in words is "twenty million, two hundred sixteen thousand, six hundred sixty-six".