21004413 has 8 divisors (see below), whose sum is σ = 28480800. Its totient is φ = 13765488.

The previous prime is 21004387. The next prime is 21004447. The reversal of 21004413 is 31440012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21004413 - 2⁸ = 21004157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21004392 and 21004401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21004463) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59158 + ... + 59511.

It is an arithmetic number, because the mean of its divisors is an integer number (3560100).

Almost surely, 2^21004413 is an apocalyptic number.

It is an amenable number.

21004413 is a deficient number, since it is larger than the sum of its proper divisors (7476387).

21004413 is a wasteful number, since it uses less digits than its factorization.

21004413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118731.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21004413 is about 4583.0571674375. The cubic root of 21004413 is about 275.9117418915.

Adding to 21004413 its reverse (31440012), we get a palindrome (52444425).

The spelling of 21004413 in words is "twenty-one million, four thousand, four hundred thirteen".