21124413 has 12 divisors (see below), whose sum is σ = 30881760. Its totient is φ = 13912776.

The previous prime is 21124391. The next prime is 21124459. The reversal of 21124413 is 31442112.

It is not a de Polignac number, because 21124413 - 2⁶ = 21124349 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21124463) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13393 + ... + 14886.

It is an arithmetic number, because the mean of its divisors is an integer number (2573480).

Almost surely, 2^21124413 is an apocalyptic number.

It is an amenable number.

21124413 is a deficient number, since it is larger than the sum of its proper divisors (9757347).

21124413 is a wasteful number, since it uses less digits than its factorization.

21124413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28368 (or 28365 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 21124413 is about 4596.1302200873. The cubic root of 21124413 is about 276.4361801941.

Adding to 21124413 its reverse (31442112), we get a palindrome (52566525).

The spelling of 21124413 in words is "twenty-one million, one hundred twenty-four thousand, four hundred thirteen".