21321124 has 24 divisors (see below), whose sum is σ = 40836096. Its totient is φ = 9660000.

The previous prime is 21321121. The next prime is 21321133. The reversal of 21321124 is 42112312.

It is a junction number, because it is equal to n+sod(n) for n = 21321098 and 21321107.

It is not an unprimeable number, because it can be changed into a prime (21321121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17949 + ... + 19099.

It is an arithmetic number, because the mean of its divisors is an integer number (1701504).

Almost surely, 2^21321124 is an apocalyptic number.

It is an amenable number.

21321124 is a deficient number, since it is larger than the sum of its proper divisors (19514972).

21321124 is a wasteful number, since it uses less digits than its factorization.

21321124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1587 (or 1585 counting only the distinct ones).

The product of its digits is 96, while the sum is 16.

The square root of 21321124 is about 4617.4802652529. The cubic root of 21321124 is about 277.2915904003.

Adding to 21321124 its reverse (42112312), we get a palindrome (63433436).

The spelling of 21321124 in words is "twenty-one million, three hundred twenty-one thousand, one hundred twenty-four".