216302121 has 18 divisors (see below), whose sum is σ = 363447162. Its totient is φ = 123600960.

The previous prime is 216302089. The next prime is 216302123. The reversal of 216302121 is 121203612.

216302121 is a `hidden beast` number, since 21 + 630 + 2 + 12 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 172265625 + 44036496 = 13125^2 + 6636^2 .

It is not a de Polignac number, because 216302121 - 2⁵ = 216302089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 216302094 and 216302103.

It is not an unprimeable number, because it can be changed into a prime (216302123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 244800 + ... + 245681.

It is an arithmetic number, because the mean of its divisors is an integer number (20191509).

Almost surely, 2^216302121 is an apocalyptic number.

216302121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

216302121 is a deficient number, since it is larger than the sum of its proper divisors (147145041).

216302121 is a wasteful number, since it uses less digits than its factorization.

216302121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 490501 (or 490491 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 216302121 is about 14707.2132302486. The cubic root of 216302121 is about 600.2796113423.

Adding to 216302121 its reverse (121203612), we get a palindrome (337505733).

The spelling of 216302121 in words is "two hundred sixteen million, three hundred two thousand, one hundred twenty-one".