216058721 has 2 divisors, whose sum is σ = 216058722. Its totient is φ = 216058720.

The previous prime is 216058697. The next prime is 216058723. The reversal of 216058721 is 127850612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 181953121 + 34105600 = 13489^2 + 5840^2 .

It is a cyclic number.

It is not a de Polignac number, because 216058721 - 2⁶ = 216058657 is a prime.

Together with 216058723, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_11917508 and since 216058721 and 11917508 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (216058723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108029360 + 108029361.

It is an arithmetic number, because the mean of its divisors is an integer number (108029361).

Almost surely, 2^216058721 is an apocalyptic number.

It is an amenable number.

216058721 is a deficient number, since it is larger than the sum of its proper divisors (1).

216058721 is an equidigital number, since it uses as much as digits as its factorization.

216058721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 216058721 is about 14698.9360499323. The cubic root of 216058721 is about 600.0543663700.

The spelling of 216058721 in words is "two hundred sixteen million, fifty-eight thousand, seven hundred twenty-one".