21021110112121 has 16 divisors (see below), whose sum is σ = 24066473169024. Its totient is φ = 17986338526464.

The previous prime is 21021110112091. The next prime is 21021110112157. The reversal of 21021110112121 is 12121101112012.

It is not a de Polignac number, because 21021110112121 - 2⁵ = 21021110112089 is a prime.

It is a super-2 number, since 2×21021110112121² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21021110112095 and 21021110112104.

It is not an unprimeable number, because it can be changed into a prime (21021116112121) 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, 56254926 + ... + 56627368.

It is an arithmetic number, because the mean of its divisors is an integer number (1504154573064).

Almost surely, 2^{21021110112121} is an apocalyptic number.

It is an amenable number.

21021110112121 is a deficient number, since it is larger than the sum of its proper divisors (3045363056903).

21021110112121 is a wasteful number, since it uses less digits than its factorization.

21021110112121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386640.

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

Adding to 21021110112121 its reverse (12121101112012), we get a palindrome (33142211224133).

The spelling of 21021110112121 in words is "twenty-one trillion, twenty-one billion, one hundred ten million, one hundred twelve thousand, one hundred twenty-one".