216669437 has 8 divisors (see below), whose sum is σ = 231521400. Its totient is φ = 202051584.

The previous prime is 216669433. The next prime is 216669443. The reversal of 216669437 is 734966612.

It can be written as a sum of positive squares in 4 ways, for example, as 97990201 + 118679236 = 9899^2 + 10894^2 .

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 216669437 - 2² = 216669433 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 (216669433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56612 + ... + 60317.

It is an arithmetic number, because the mean of its divisors is an integer number (28940175).

Almost surely, 2^216669437 is an apocalyptic number.

It is an amenable number.

216669437 is a deficient number, since it is larger than the sum of its proper divisors (14851963).

216669437 is a wasteful number, since it uses less digits than its factorization.

216669437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117055.

The product of its digits is 326592, while the sum is 44.

The square root of 216669437 is about 14719.6955471232. The cubic root of 216669437 is about 600.6192098196.

The spelling of 216669437 in words is "two hundred sixteen million, six hundred sixty-nine thousand, four hundred thirty-seven".