21101111211121 has 8 divisors (see below), whose sum is σ = 21108220878240. Its totient is φ = 21094001883168.

The previous prime is 21101111211097. The next prime is 21101111211137. The reversal of 21101111211121 is 12111211110112.

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 21101111211121 - 2¹³ = 21101111202929 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21101111211095 and 21101111211104.

It is not an unprimeable number, because it can be changed into a prime (21101111211151) 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, 207337170 + ... + 207438916.

It is an arithmetic number, because the mean of its divisors is an integer number (2638527609780).

Almost surely, 2^{21101111211121} is an apocalyptic number.

It is an amenable number.

21101111211121 is a deficient number, since it is larger than the sum of its proper divisors (7109667119).

21101111211121 is a wasteful number, since it uses less digits than its factorization.

21101111211121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169583.

The product of its (nonzero) digits is 8, while the sum is 16.

Adding to 21101111211121 its reverse (12111211110112), we get a palindrome (33212322321233).

The spelling of 21101111211121 in words is "twenty-one trillion, one hundred one billion, one hundred eleven million, two hundred eleven thousand, one hundred twenty-one".