21012110211121 has 4 divisors (see below), whose sum is σ = 21012244873252. Its totient is φ = 21011975548992.

The previous prime is 21012110211107. The next prime is 21012110211137. The reversal of 21012110211121 is 12111201121012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6597521022096 + 14414589189025 = 2568564^2 + 3796655^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012110211121 - 2⁵ = 21012110211089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21012110211095 and 21012110211104.

It is not an unprimeable number, because it can be changed into a prime (21012110811121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67096740 + ... + 67409173.

It is an arithmetic number, because the mean of its divisors is an integer number (5253061218313).

Almost surely, 2^{21012110211121} is an apocalyptic number.

It is an amenable number.

21012110211121 is a deficient number, since it is larger than the sum of its proper divisors (134662131).

21012110211121 is a wasteful number, since it uses less digits than its factorization.

21012110211121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134662130.

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

Adding to 21012110211121 its reverse (12111201121012), we get a palindrome (33123311332133).

The spelling of 21012110211121 in words is "twenty-one trillion, twelve billion, one hundred ten million, two hundred eleven thousand, one hundred twenty-one".