21313434 has 32 divisors (see below), whose sum is σ = 44349120. Its totient is φ = 6820352.

The previous prime is 21313429. The next prime is 21313447. The reversal of 21313434 is 43431312.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21313434.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60202 + ... + 60554.

It is an arithmetic number, because the mean of its divisors is an integer number (1385910).

Almost surely, 2^21313434 is an apocalyptic number.

21313434 is an abundant number, since it is smaller than the sum of its proper divisors (23035686).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21313434 is a wasteful number, since it uses less digits than its factorization.

21313434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 734.

The product of its digits is 864, while the sum is 21.

The square root of 21313434 is about 4616.6474849180. The cubic root of 21313434 is about 277.2582489944.

Adding to 21313434 its reverse (43431312), we get a palindrome (64744746).

It can be divided in two parts, 2131 and 3434, that added together give a triangular number (5565 = T₁₀₅).

The spelling of 21313434 in words is "twenty-one million, three hundred thirteen thousand, four hundred thirty-four".