21041310121 has 4 divisors (see below), whose sum is σ = 22659872452. Its totient is φ = 19422747792.

The previous prime is 21041310083. The next prime is 21041310127. The reversal of 21041310121 is 12101314012.

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 6795694096 + 14245616025 = 82436^2 + 119355^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21041310121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21041310095 and 21041310104.

It is not an unprimeable number, because it can be changed into a prime (21041310127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 809281146 + ... + 809281171.

It is an arithmetic number, because the mean of its divisors is an integer number (5664968113).

Almost surely, 2^21041310121 is an apocalyptic number.

It is an amenable number.

21041310121 is a deficient number, since it is larger than the sum of its proper divisors (1618562331).

21041310121 is a wasteful number, since it uses less digits than its factorization.

21041310121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1618562330.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21041310121 its reverse (12101314012), we get a palindrome (33142624133).

The spelling of 21041310121 in words is "twenty-one billion, forty-one million, three hundred ten thousand, one hundred twenty-one".