216999555 has 8 divisors (see below), whose sum is σ = 347199312. Its totient is φ = 115733088.

The previous prime is 216999553. The next prime is 216999569. The reversal of 216999555 is 555999612.

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

It is not a de Polignac number, because 216999555 - 2¹ = 216999553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 216999498 and 216999507.

It is not an unprimeable number, because it can be changed into a prime (216999553) 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, 7233304 + ... + 7233333.

It is an arithmetic number, because the mean of its divisors is an integer number (43399914).

Almost surely, 2^216999555 is an apocalyptic number.

216999555 is a deficient number, since it is larger than the sum of its proper divisors (130199757).

216999555 is a wasteful number, since it uses less digits than its factorization.

216999555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14466645.

The product of its digits is 1093500, while the sum is 51.

The square root of 216999555 is about 14730.9047583643. The cubic root of 216999555 is about 600.9240899213.

The spelling of 216999555 in words is "two hundred sixteen million, nine hundred ninety-nine thousand, five hundred fifty-five".