216424666 has 4 divisors (see below), whose sum is σ = 324637002. Its totient is φ = 108212332.

The previous prime is 216424643. The next prime is 216424667. The reversal of 216424666 is 666424612.

216424666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 121771225 + 94653441 = 11035^2 + 9729^2 .

It is not an unprimeable number, because it can be changed into a prime (216424667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54106165 + ... + 54106168.

Almost surely, 2^216424666 is an apocalyptic number.

216424666 is a deficient number, since it is larger than the sum of its proper divisors (108212336).

216424666 is a wasteful number, since it uses less digits than its factorization.

216424666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108212335.

The product of its digits is 82944, while the sum is 37.

The square root of 216424666 is about 14711.3787933015. The cubic root of 216424666 is about 600.3929518511.

The spelling of 216424666 in words is "two hundred sixteen million, four hundred twenty-four thousand, six hundred sixty-six".