21313535 has 16 divisors (see below), whose sum is σ = 27112800. Its totient is φ = 16039296.

The previous prime is 21313531. The next prime is 21313541. The reversal of 21313535 is 53531312.

It is a cyclic number.

It is not a de Polignac number, because 21313535 - 2² = 21313531 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21313535.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21313531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14201 + ... + 15629.

It is an arithmetic number, because the mean of its divisors is an integer number (1694550).

Almost surely, 2^21313535 is an apocalyptic number.

21313535 is a deficient number, since it is larger than the sum of its proper divisors (5799265).

21313535 is a wasteful number, since it uses less digits than its factorization.

21313535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1610.

The product of its digits is 1350, while the sum is 23.

The square root of 21313535 is about 4616.6584235787. The cubic root of 21313535 is about 277.2586869504.

Adding to 21313535 its reverse (53531312), we get a palindrome (74844847).

The spelling of 21313535 in words is "twenty-one million, three hundred thirteen thousand, five hundred thirty-five".