21001020211121 has 8 divisors (see below), whose sum is σ = 21201183561600. Its totient is φ = 20801557959120.

The previous prime is 21001020211057. The next prime is 21001020211147. The reversal of 21001020211121 is 12111202010012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21001020211121 - 2⁶ = 21001020211057 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001020211096 and 21001020211105.

It is not an unprimeable number, because it can be changed into a prime (21001020211321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175214426 + ... + 175334243.

It is an arithmetic number, because the mean of its divisors is an integer number (2650147945200).

Almost surely, 2^{21001020211121} is an apocalyptic number.

It is an amenable number.

21001020211121 is a deficient number, since it is larger than the sum of its proper divisors (200163350479).

21001020211121 is a wasteful number, since it uses less digits than its factorization.

21001020211121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350549239.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21001020211121 its reverse (12111202010012), we get a palindrome (33112222221133).

The spelling of 21001020211121 in words is "twenty-one trillion, one billion, twenty million, two hundred eleven thousand, one hundred twenty-one".