21021021001121 has 16 divisors (see below), whose sum is σ = 22030185922704. Its totient is φ = 20036250134784.

The previous prime is 21021021001111. The next prime is 21021021001133. The reversal of 21021021001121 is 12110012012012.

It can be written as a sum of positive squares in 8 ways, for example, as 15628750225 + 21005392250896 = 125015^2 + 4583164^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021021001121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21021021001096 and 21021021001105.

It is not an unprimeable number, because it can be changed into a prime (21021021001111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6927386 + ... + 9488451.

It is an arithmetic number, because the mean of its divisors is an integer number (1376886620169).

Almost surely, 2^{21021021001121} is an apocalyptic number.

It is an amenable number.

21021021001121 is a deficient number, since it is larger than the sum of its proper divisors (1009164921583).

21021021001121 is a wasteful number, since it uses less digits than its factorization.

21021021001121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16416580.

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

Adding to 21021021001121 its reverse (12110012012012), we get a palindrome (33131033013133).

The spelling of 21021021001121 in words is "twenty-one trillion, twenty-one billion, twenty-one million, one thousand, one hundred twenty-one".