21013124 has 12 divisors (see below), whose sum is σ = 40116048. Its totient is φ = 9551400.

The previous prime is 21013117. The next prime is 21013127. The reversal of 21013124 is 42131012.

It is a junction number, because it is equal to n+sod(n) for n = 21013099 and 21013108.

It is not an unprimeable number, because it can be changed into a prime (21013127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 238742 + ... + 238829.

It is an arithmetic number, because the mean of its divisors is an integer number (3343004).

Almost surely, 2^21013124 is an apocalyptic number.

It is an amenable number.

21013124 is a deficient number, since it is larger than the sum of its proper divisors (19102924).

21013124 is a wasteful number, since it uses less digits than its factorization.

21013124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477586 (or 477584 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21013124 is about 4584.0074170970. The cubic root of 21013124 is about 275.9498788774.

Adding to 21013124 its reverse (42131012), we get a palindrome (63144136).

It can be divided in two parts, 2101 and 3124, that added together give a palindrome (5225).

The spelling of 21013124 in words is "twenty-one million, thirteen thousand, one hundred twenty-four".