216677309 has 4 divisors (see below), whose sum is σ = 217417116. Its totient is φ = 215937504.

The previous prime is 216677297. The next prime is 216677317. The reversal of 216677309 is 903776612.

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 145274809 + 71402500 = 12053^2 + 8450^2 .

It is a cyclic number.

It is not a de Polignac number, because 216677309 - 2¹² = 216673213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216677389) 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, 369464 + ... + 370049.

It is an arithmetic number, because the mean of its divisors is an integer number (54354279).

Almost surely, 2^216677309 is an apocalyptic number.

It is an amenable number.

216677309 is a deficient number, since it is larger than the sum of its proper divisors (739807).

216677309 is an equidigital number, since it uses as much as digits as its factorization.

216677309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 739806.

The product of its (nonzero) digits is 95256, while the sum is 41.

The square root of 216677309 is about 14719.9629415294. The cubic root of 216677309 is about 600.6264835991.

The spelling of 216677309 in words is "two hundred sixteen million, six hundred seventy-seven thousand, three hundred nine".