21011221022121 has 48 divisors (see below), whose sum is σ = 33603980137728. Its totient is φ = 12543552885600.

The previous prime is 21011221022111. The next prime is 21011221022149. The reversal of 21011221022121 is 12122012211012.

21011221022121 is a `hidden beast` number, since 210 + 1 + 1 + 2 + 210 + 221 + 21 = 666.

It is not a de Polignac number, because 21011221022121 - 2⁵ = 21011221022089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21011221022094 and 21011221022103.

It is not an unprimeable number, because it can be changed into a prime (21011221022111) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 290933706 + ... + 291005916.

It is an arithmetic number, because the mean of its divisors is an integer number (700082919536).

Almost surely, 2^{21011221022121} is an apocalyptic number.

It is an amenable number.

21011221022121 is a deficient number, since it is larger than the sum of its proper divisors (12592759115607).

21011221022121 is a wasteful number, since it uses less digits than its factorization.

21011221022121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116162 (or 116159 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21011221022121 its reverse (12122012211012), we get a palindrome (33133233233133).

The spelling of 21011221022121 in words is "twenty-one trillion, eleven billion, two hundred twenty-one million, twenty-two thousand, one hundred twenty-one".