216902309 has 8 divisors (see below), whose sum is σ = 245881440. Its totient is φ = 189679536.

The previous prime is 216902293. The next prime is 216902417. The reversal of 216902309 is 903209612.

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

It is a cyclic number.

It is not a de Polignac number, because 216902309 - 2⁴ = 216902293 is a prime.

It is a super-2 number, since 2×216902309² = 94093223299062962, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216902209) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 438827 + ... + 439320.

It is an arithmetic number, because the mean of its divisors is an integer number (30735180).

Almost surely, 2^216902309 is an apocalyptic number.

It is an amenable number.

216902309 is a deficient number, since it is larger than the sum of its proper divisors (28979131).

216902309 is a wasteful number, since it uses less digits than its factorization.

216902309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 878179.

The product of its (nonzero) digits is 5832, while the sum is 32.

The square root of 216902309 is about 14727.6036407828. The cubic root of 216902309 is about 600.8343106348.

The spelling of 216902309 in words is "two hundred sixteen million, nine hundred two thousand, three hundred nine".