21121130421 has 12 divisors (see below), whose sum is σ = 30525785472. Its totient is φ = 14072683176.

The previous prime is 21121130419. The next prime is 21121130453. The reversal of 21121130421 is 12403112112.

21121130421 is a `hidden beast` number, since 2 + 1 + 1 + 211 + 30 + 421 = 666.

It is not a de Polignac number, because 21121130421 - 2¹ = 21121130419 is a prime.

It is a super-2 number, since 2×21121130421² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21121130394 and 21121130403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121130491) 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 11 ways as a sum of consecutive naturals, for example, 655941 + ... + 687386.

It is an arithmetic number, because the mean of its divisors is an integer number (2543815456).

Almost surely, 2^21121130421 is an apocalyptic number.

It is an amenable number.

21121130421 is a deficient number, since it is larger than the sum of its proper divisors (9404655051).

21121130421 is a wasteful number, since it uses less digits than its factorization.

21121130421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1345080 (or 1345077 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 21121130421 its reverse (12403112112), we get a palindrome (33524242533).

The spelling of 21121130421 in words is "twenty-one billion, one hundred twenty-one million, one hundred thirty thousand, four hundred twenty-one".