21021121201 has 2 divisors, whose sum is σ = 21021121202. Its totient is φ = 21021121200.

The previous prime is 21021121117. The next prime is 21021121241. The reversal of 21021121201 is 10212112012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12382348176 + 8638773025 = 111276^2 + 92945^2 .

It is a cyclic number.

It is not a de Polignac number, because 21021121201 - 2¹⁷ = 21020990129 is a prime.

It is not a weakly prime, because it can be changed into another prime (21021121241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510560600 + 10510560601.

It is an arithmetic number, because the mean of its divisors is an integer number (10510560601).

Almost surely, 2^21021121201 is an apocalyptic number.

It is an amenable number.

21021121201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021121201 is an equidigital number, since it uses as much as digits as its factorization.

21021121201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21021121201 its reverse (10212112012), we get a palindrome (31233233213).

The spelling of 21021121201 in words is "twenty-one billion, twenty-one million, one hundred twenty-one thousand, two hundred one".