216644859 has 12 divisors (see below), whose sum is σ = 329401800. Its totient is φ = 136828224.

The previous prime is 216644849. The next prime is 216644887. The reversal of 216644859 is 958446612.

216644859 is a `hidden beast` number, since 2 + 166 + 4 + 485 + 9 = 666.

It is not a de Polignac number, because 216644859 - 2²⁴ = 199867643 is a prime.

It is a super-3 number, since 3×216644859³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (216644839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 633294 + ... + 633635.

It is an arithmetic number, because the mean of its divisors is an integer number (27450150).

Almost surely, 2^216644859 is an apocalyptic number.

216644859 is a deficient number, since it is larger than the sum of its proper divisors (112756941).

216644859 is a wasteful number, since it uses less digits than its factorization.

216644859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1266954 (or 1266951 counting only the distinct ones).

The product of its digits is 414720, while the sum is 45.

The square root of 216644859 is about 14718.8606556350. The cubic root of 216644859 is about 600.5964984528.

The spelling of 216644859 in words is "two hundred sixteen million, six hundred forty-four thousand, eight hundred fifty-nine".