21031120424 has 32 divisors (see below), whose sum is σ = 39870563040. Its totient is φ = 10399521600.

The previous prime is 21031120423. The next prime is 21031120433. The reversal of 21031120424 is 42402113012.

It is a junction number, because it is equal to n+sod(n) for n = 21031120396 and 21031120405.

It is not an unprimeable number, because it can be changed into a prime (21031120423) 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 7 ways as a sum of consecutive naturals, for example, 272819 + ... + 341309.

It is an arithmetic number, because the mean of its divisors is an integer number (1245955095).

Almost surely, 2^21031120424 is an apocalyptic number.

It is an amenable number.

21031120424 is a deficient number, since it is larger than the sum of its proper divisors (18839442616).

21031120424 is a wasteful number, since it uses less digits than its factorization.

21031120424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68921 (or 68917 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21031120424 its reverse (42402113012), we get a palindrome (63433233436).

The spelling of 21031120424 in words is "twenty-one billion, thirty-one million, one hundred twenty thousand, four hundred twenty-four".