216420361 has 2 divisors, whose sum is σ = 216420362. Its totient is φ = 216420360.

The previous prime is 216420313. The next prime is 216420371. The reversal of 216420361 is 163024612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 194742025 + 21678336 = 13955^2 + 4656^2 .

It is a cyclic number.

It is not a de Polignac number, because 216420361 - 2¹³ = 216412169 is a prime.

It is not a weakly prime, because it can be changed into another prime (216420311) 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 as a sum of consecutive naturals, namely, 108210180 + 108210181.

It is an arithmetic number, because the mean of its divisors is an integer number (108210181).

Almost surely, 2^216420361 is an apocalyptic number.

It is an amenable number.

216420361 is a deficient number, since it is larger than the sum of its proper divisors (1).

216420361 is an equidigital number, since it uses as much as digits as its factorization.

216420361 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 216420361 is about 14711.2324772604. The cubic root of 216420361 is about 600.3889709297.

Adding to 216420361 its reverse (163024612), we get a palindrome (379444973).

The spelling of 216420361 in words is "two hundred sixteen million, four hundred twenty thousand, three hundred sixty-one".