21163201 has 2 divisors, whose sum is σ = 21163202. Its totient is φ = 21163200.

The previous prime is 21163199. The next prime is 21163229. The reversal of 21163201 is 10236112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11553201 + 9610000 = 3399^2 + 3100^2 .

It is a cyclic number.

It is not a de Polignac number, because 21163201 - 2¹ = 21163199 is a prime.

Together with 21163199, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21163291) 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, 10581600 + 10581601.

It is an arithmetic number, because the mean of its divisors is an integer number (10581601).

Almost surely, 2^21163201 is an apocalyptic number.

It is an amenable number.

21163201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21163201 is an equidigital number, since it uses as much as digits as its factorization.

21163201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 21163201 is about 4600.3479216251. The cubic root of 21163201 is about 276.6052712915.

Adding to 21163201 its reverse (10236112), we get a palindrome (31399313).

The spelling of 21163201 in words is "twenty-one million, one hundred sixty-three thousand, two hundred one".