21121404430 has 24 divisors (see below), whose sum is σ = 44225635608. Its totient is φ = 7241624208.

The previous prime is 21121404419. The next prime is 21121404431. The reversal of 21121404430 is 3440412112.

It is a happy number.

It is a super-2 number, since 2×21121404430² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121404431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21551964 + ... + 21552943.

It is an arithmetic number, because the mean of its divisors is an integer number (1842734817).

Almost surely, 2^21121404430 is an apocalyptic number.

21121404430 is an abundant number, since it is smaller than the sum of its proper divisors (23104231178).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21121404430 is a wasteful number, since it uses less digits than its factorization.

21121404430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43104928 (or 43104921 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21121404430 its reverse (3440412112), we get a palindrome (24561816542).

The spelling of 21121404430 in words is "twenty-one billion, one hundred twenty-one million, four hundred four thousand, four hundred thirty".