216020251 has 2 divisors, whose sum is σ = 216020252. Its totient is φ = 216020250.

The previous prime is 216020239. The next prime is 216020257. The reversal of 216020251 is 152020612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216020251 - 2⁵ = 216020219 is a prime.

It is not a weakly prime, because it can be changed into another prime (216020257) 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, 108010125 + 108010126.

It is an arithmetic number, because the mean of its divisors is an integer number (108010126).

Almost surely, 2^216020251 is an apocalyptic number.

216020251 is a deficient number, since it is larger than the sum of its proper divisors (1).

216020251 is an equidigital number, since it uses as much as digits as its factorization.

216020251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 216020251 is about 14697.6273935625. The cubic root of 216020251 is about 600.0187503400.

Adding to 216020251 its reverse (152020612), we get a palindrome (368040863).

The spelling of 216020251 in words is "two hundred sixteen million, twenty thousand, two hundred fifty-one".