21405334 has 8 divisors (see below), whose sum is σ = 32426208. Its totient is φ = 10596600.

The previous prime is 21405313. The next prime is 21405337. The reversal of 21405334 is 43350412.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21405337) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 52782 + ... + 53185.

It is an arithmetic number, because the mean of its divisors is an integer number (4053276).

Almost surely, 2^21405334 is an apocalyptic number.

21405334 is a deficient number, since it is larger than the sum of its proper divisors (11020874).

21405334 is a wasteful number, since it uses less digits than its factorization.

21405334 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106070.

The product of its (nonzero) digits is 1440, while the sum is 22.

The square root of 21405334 is about 4626.5898888922. The cubic root of 21405334 is about 277.6561748388.

Adding to 21405334 its reverse (43350412), we get a palindrome (64755746).

The spelling of 21405334 in words is "twenty-one million, four hundred five thousand, three hundred thirty-four".