21012221121211 has 32 divisors (see below), whose sum is σ = 22725805036032. Its totient is φ = 19380882892800.

The previous prime is 21012221121173. The next prime is 21012221121223. The reversal of 21012221121211 is 11212112221012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21012221121211 - 2¹¹ = 21012221119163 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21012221121271) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18989136 + ... + 20065186.

It is an arithmetic number, because the mean of its divisors is an integer number (710181407376).

Almost surely, 2^{21012221121211} is an apocalyptic number.

21012221121211 is a deficient number, since it is larger than the sum of its proper divisors (1713583914821).

21012221121211 is a wasteful number, since it uses less digits than its factorization.

21012221121211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1076403.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21012221121211 its reverse (11212112221012), we get a palindrome (32224333342223).

The spelling of 21012221121211 in words is "twenty-one trillion, twelve billion, two hundred twenty-one million, one hundred twenty-one thousand, two hundred eleven".