21021121234121 has 24 divisors (see below), whose sum is σ = 21724552301760. Its totient is φ = 20339744023872.

The previous prime is 21021121234027. The next prime is 21021121234229. The reversal of 21021121234121 is 12143212112012.

It is a de Polignac number, because none of the positive numbers 2^k-21021121234121 is a prime.

It is a super-2 number, since 2×21021121234121² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21021121234921) 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 23 ways as a sum of consecutive naturals, for example, 184447271 + ... + 184561203.

It is an arithmetic number, because the mean of its divisors is an integer number (905189679240).

Almost surely, 2^{21021121234121} is an apocalyptic number.

It is an amenable number.

21021121234121 is a deficient number, since it is larger than the sum of its proper divisors (703431067639).

21021121234121 is a wasteful number, since it uses less digits than its factorization.

21021121234121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114753 (or 114716 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 23.

Adding to 21021121234121 its reverse (12143212112012), we get a palindrome (33164333346133).

The spelling of 21021121234121 in words is "twenty-one trillion, twenty-one billion, one hundred twenty-one million, two hundred thirty-four thousand, one hundred twenty-one".