216027209 has 4 divisors (see below), whose sum is σ = 218009220. Its totient is φ = 214045200.

The previous prime is 216027197. The next prime is 216027223. The reversal of 216027209 is 902720612.

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

It can be written as a sum of positive squares in 2 ways, for example, as 76125625 + 139901584 = 8725^2 + 11828^2 .

It is a cyclic number.

It is not a de Polignac number, because 216027209 - 2⁸ = 216026953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216027239) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 990842 + ... + 991059.

It is an arithmetic number, because the mean of its divisors is an integer number (54502305).

Almost surely, 2^216027209 is an apocalyptic number.

It is an amenable number.

216027209 is a deficient number, since it is larger than the sum of its proper divisors (1982011).

216027209 is a wasteful number, since it uses less digits than its factorization.

216027209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1982010.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 216027209 is about 14697.8640965278. The cubic root of 216027209 is about 600.0251924607.

The spelling of 216027209 in words is "two hundred sixteen million, twenty-seven thousand, two hundred nine".