216721063 has 4 divisors (see below), whose sum is σ = 233391928. Its totient is φ = 200050200.

The previous prime is 216721033. The next prime is 216721069. The reversal of 216721063 is 360127612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 216721063 - 2²¹ = 214623911 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 (216721069) 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 3 ways as a sum of consecutive naturals, for example, 8335413 + ... + 8335438.

It is an arithmetic number, because the mean of its divisors is an integer number (58347982).

Almost surely, 2^216721063 is an apocalyptic number.

216721063 is a deficient number, since it is larger than the sum of its proper divisors (16670865).

216721063 is a wasteful number, since it uses less digits than its factorization.

216721063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16670864.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 216721063 is about 14721.4490794894. The cubic root of 216721063 is about 600.6669093711. Note that the first 3 decimals are identical.

Adding to 216721063 its reverse (360127612), we get a palindrome (576848675).

The spelling of 216721063 in words is "two hundred sixteen million, seven hundred twenty-one thousand, sixty-three".