21221210011121 has 16 divisors (see below), whose sum is σ = 22366521811200. Its totient is φ = 20078742008448.

The previous prime is 21221210011081. The next prime is 21221210011123. The reversal of 21221210011121 is 12111001212212.

It is a cyclic number.

It is not a de Polignac number, because 21221210011121 - 2¹⁰ = 21221210010097 is a prime.

It is a super-2 number, since 2×21221210011121² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21221210011121.

It is not an unprimeable number, because it can be changed into a prime (21221210011123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 311095400 + ... + 311163606.

It is an arithmetic number, because the mean of its divisors is an integer number (1397907613200).

Almost surely, 2^{21221210011121} is an apocalyptic number.

It is an amenable number.

21221210011121 is a deficient number, since it is larger than the sum of its proper divisors (1145311800079).

21221210011121 is a wasteful number, since it uses less digits than its factorization.

21221210011121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88808.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21221210011121 its reverse (12111001212212), we get a palindrome (33332211223333).

The spelling of 21221210011121 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred ten million, eleven thousand, one hundred twenty-one".