216821867 has 8 divisors (see below), whose sum is σ = 223284336. Its totient is φ = 210424032.

The previous prime is 216821809. The next prime is 216821921. The reversal of 216821867 is 768128612.

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 216821867 - 2¹⁴ = 216805483 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216821807) 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, 9308 + ... + 22809.

It is an arithmetic number, because the mean of its divisors is an integer number (27910542).

Almost surely, 2^216821867 is an apocalyptic number.

216821867 is a deficient number, since it is larger than the sum of its proper divisors (6462469).

216821867 is a wasteful number, since it uses less digits than its factorization.

216821867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32317.

The product of its digits is 64512, while the sum is 41.

The square root of 216821867 is about 14724.8723933350. The cubic root of 216821867 is about 600.7600248269.

The spelling of 216821867 in words is "two hundred sixteen million, eight hundred twenty-one thousand, eight hundred sixty-seven".