21112121010121 has 4 divisors (see below), whose sum is σ = 21123935293392. Its totient is φ = 21100306726852.

The previous prime is 21112121010107. The next prime is 21112121010139. The reversal of 21112121010121 is 12101012121112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21112121010121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21112121010095 and 21112121010104.

It is not an unprimeable number, because it can be changed into a prime (21112121010221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5907138955 + ... + 5907142528.

It is an arithmetic number, because the mean of its divisors is an integer number (5280983823348).

Almost surely, 2^{21112121010121} is an apocalyptic number.

It is an amenable number.

21112121010121 is a deficient number, since it is larger than the sum of its proper divisors (11814283271).

21112121010121 is a wasteful number, since it uses less digits than its factorization.

21112121010121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11814283270.

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

Adding to 21112121010121 its reverse (12101012121112), we get a palindrome (33213133131233).

It can be divided in two parts, 21112 and 121010121, that multiplied together give a palindrome (2554765674552).

The spelling of 21112121010121 in words is "twenty-one trillion, one hundred twelve billion, one hundred twenty-one million, ten thousand, one hundred twenty-one".