21104613 has 12 divisors (see below), whose sum is σ = 30871360. Its totient is φ = 13891176.

The previous prime is 21104591. The next prime is 21104641. The reversal of 21104613 is 31640112.

It is a happy number.

It is not a de Polignac number, because 21104613 - 2⁶ = 21104549 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21104683) 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 11 ways as a sum of consecutive naturals, for example, 14131 + ... + 15552.

Almost surely, 2^21104613 is an apocalyptic number.

It is an amenable number.

21104613 is a deficient number, since it is larger than the sum of its proper divisors (9766747).

21104613 is a wasteful number, since it uses less digits than its factorization.

21104613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29768 (or 29765 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 21104613 is about 4593.9757291479. The cubic root of 21104613 is about 276.3497849358.

Adding to 21104613 its reverse (31640112), we get a palindrome (52744725).

The spelling of 21104613 in words is "twenty-one million, one hundred four thousand, six hundred thirteen".