21010103031121 has 4 divisors (see below), whose sum is σ = 21011204612772. Its totient is φ = 21009001449472.

The previous prime is 21010103031103. The next prime is 21010103031143. The reversal of 21010103031121 is 12113030101012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 138134128896 + 20871968902225 = 371664^2 + 4568585^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010103031121 - 2²⁵ = 21010069476689 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21010103031095 and 21010103031104.

It is not an unprimeable number, because it can be changed into a prime (21010103031221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 550762216 + ... + 550800361.

It is an arithmetic number, because the mean of its divisors is an integer number (5252801153193).

Almost surely, 2^{21010103031121} is an apocalyptic number.

It is an amenable number.

21010103031121 is a deficient number, since it is larger than the sum of its proper divisors (1101581651).

21010103031121 is a wasteful number, since it uses less digits than its factorization.

21010103031121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1101581650.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 21010103031121 its reverse (12113030101012), we get a palindrome (33123133132133).

The spelling of 21010103031121 in words is "twenty-one trillion, ten billion, one hundred three million, thirty-one thousand, one hundred twenty-one".