21002011111121 has 16 divisors (see below), whose sum is σ = 22062706176000. Its totient is φ = 19965759282000.

The previous prime is 21002011111087. The next prime is 21002011111157. The reversal of 21002011111121 is 12111111020012.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21002011111121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21002011111096 and 21002011111105.

It is not an unprimeable number, because it can be changed into a prime (21002011111181) 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, 1545155 + ... + 6662696.

It is an arithmetic number, because the mean of its divisors is an integer number (1378919136000).

Almost surely, 2^{21002011111121} is an apocalyptic number.

It is an amenable number.

21002011111121 is a deficient number, since it is larger than the sum of its proper divisors (1060695064879).

21002011111121 is a wasteful number, since it uses less digits than its factorization.

21002011111121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8209340.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21002011111121 its reverse (12111111020012), we get a palindrome (33113122131133).

The spelling of 21002011111121 in words is "twenty-one trillion, two billion, eleven million, one hundred eleven thousand, one hundred twenty-one".