21000300281 has 2 divisors, whose sum is σ = 21000300282. Its totient is φ = 21000300280.

The previous prime is 21000300199. The next prime is 21000300289. The reversal of 21000300281 is 18200300012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10579973881 + 10420326400 = 102859^2 + 102080^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21000300281 is a prime.

It is a super-2 number, since 2×21000300281² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21000300289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500150140 + 10500150141.

It is an arithmetic number, because the mean of its divisors is an integer number (10500150141).

Almost surely, 2^21000300281 is an apocalyptic number.

It is an amenable number.

21000300281 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000300281 is an equidigital number, since it uses as much as digits as its factorization.

21000300281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21000300281 its reverse (18200300012), we get a palindrome (39200600293).

The spelling of 21000300281 in words is "twenty-one billion, three hundred thousand, two hundred eighty-one".