21121044211 has 2 divisors, whose sum is σ = 21121044212. Its totient is φ = 21121044210.

The previous prime is 21121044089. The next prime is 21121044251. The reversal of 21121044211 is 11244012112.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21121044211 - 2¹³ = 21121036019 is a prime.

It is a super-2 number, since 2×21121044211² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21121044251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560522105 + 10560522106.

It is an arithmetic number, because the mean of its divisors is an integer number (10560522106).

Almost surely, 2^21121044211 is an apocalyptic number.

21121044211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121044211 is an equidigital number, since it uses as much as digits as its factorization.

21121044211 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21121044211 its reverse (11244012112), we get a palindrome (32365056323).

The spelling of 21121044211 in words is "twenty-one billion, one hundred twenty-one million, forty-four thousand, two hundred eleven".