216303021 has 16 divisors (see below), whose sum is σ = 349581120. Its totient is φ = 131092560.

The previous prime is 216303007. The next prime is 216303023. The reversal of 216303021 is 120303612.

216303021 is a `hidden beast` number, since 2 + 1 + 630 + 30 + 2 + 1 = 666.

216303021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 216303021 - 2¹⁵ = 216270253 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 216302985 and 216303003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216303023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 363850 + ... + 364443.

It is an arithmetic number, because the mean of its divisors is an integer number (21848820).

Almost surely, 2^216303021 is an apocalyptic number.

It is an amenable number.

216303021 is a deficient number, since it is larger than the sum of its proper divisors (133278099).

216303021 is a wasteful number, since it uses less digits than its factorization.

216303021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 728313 (or 728307 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 216303021 is about 14707.2438274478. The cubic root of 216303021 is about 600.2804438983.

Adding to 216303021 its reverse (120303612), we get a palindrome (336606633).

The spelling of 216303021 in words is "two hundred sixteen million, three hundred three thousand, twenty-one".