216548666 has 4 divisors (see below), whose sum is σ = 324823002. Its totient is φ = 108274332.

The previous prime is 216548663. The next prime is 216548699. The reversal of 216548666 is 666845612.

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., 168454441 + 48094225 = 12979^2 + 6935^2 .

It is not an unprimeable number, because it can be changed into a prime (216548663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54137165 + ... + 54137168.

Almost surely, 2^216548666 is an apocalyptic number.

216548666 is a deficient number, since it is larger than the sum of its proper divisors (108274336).

216548666 is a wasteful number, since it uses less digits than its factorization.

216548666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108274335.

The product of its digits is 414720, while the sum is 44.

The square root of 216548666 is about 14715.5926146384. The cubic root of 216548666 is about 600.5075945326.

The spelling of 216548666 in words is "two hundred sixteen million, five hundred forty-eight thousand, six hundred sixty-six".