21201011121 has 16 divisors (see below), whose sum is σ = 29864966400. Its totient is φ = 13356271488.

The previous prime is 21201011087. The next prime is 21201011141. The reversal of 21201011121 is 12111010212.

It is not a de Polignac number, because 21201011121 - 2¹⁹ = 21200486833 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21201011097 and 21201011106.

It is not an unprimeable number, because it can be changed into a prime (21201011141) 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, 2588356 + ... + 2596533.

It is an arithmetic number, because the mean of its divisors is an integer number (1866560400).

Almost surely, 2^21201011121 is an apocalyptic number.

It is an amenable number.

21201011121 is a deficient number, since it is larger than the sum of its proper divisors (8663955279).

21201011121 is a wasteful number, since it uses less digits than its factorization.

21201011121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5184968.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21201011121 its reverse (12111010212), we get a palindrome (33312021333).

Subtracting from 21201011121 its reverse (12111010212), we obtain a palindrome (9090000909).

The spelling of 21201011121 in words is "twenty-one billion, two hundred one million, eleven thousand, one hundred twenty-one".