21200281 has 2 divisors, whose sum is σ = 21200282. Its totient is φ = 21200280.

The previous prime is 21200279. The next prime is 21200303. The reversal of 21200281 is 18200212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17264025 + 3936256 = 4155^2 + 1984^2 .

It is a cyclic number.

It is not a de Polignac number, because 21200281 - 2¹ = 21200279 is a prime.

It is a super-2 number, since 2×21200281² = 898903828957922, which contains 22 as substring.

Together with 21200279, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21200381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600140 + 10600141.

It is an arithmetic number, because the mean of its divisors is an integer number (10600141).

Almost surely, 2^21200281 is an apocalyptic number.

It is an amenable number.

21200281 is a deficient number, since it is larger than the sum of its proper divisors (1).

21200281 is an equidigital number, since it uses as much as digits as its factorization.

21200281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 21200281 is about 4604.3762878375. The cubic root of 21200281 is about 276.7667235396.

Adding to 21200281 its reverse (18200212), we get a palindrome (39400493).

The spelling of 21200281 in words is "twenty-one million, two hundred thousand, two hundred eighty-one".