21004213124 has 24 divisors (see below), whose sum is σ = 37600210368. Its totient is φ = 10262876000.

The previous prime is 21004213093. The next prime is 21004213151. The reversal of 21004213124 is 42131240012.

It is a junction number, because it is equal to n+sod(n) for n = 21004213096 and 21004213105.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 144152 + ... + 250575.

It is an arithmetic number, because the mean of its divisors is an integer number (1566675432).

Almost surely, 2^21004213124 is an apocalyptic number.

It is an amenable number.

21004213124 is a deficient number, since it is larger than the sum of its proper divisors (16595997244).

21004213124 is a wasteful number, since it uses less digits than its factorization.

21004213124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395035 (or 395033 counting only the distinct ones).

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

Adding to 21004213124 its reverse (42131240012), we get a palindrome (63135453136).

The spelling of 21004213124 in words is "twenty-one billion, four million, two hundred thirteen thousand, one hundred twenty-four".