21321434 has 8 divisors (see below), whose sum is σ = 33863508. Its totient is φ = 10033600.

The previous prime is 21321431. The next prime is 21321449. The reversal of 21321434 is 43412312.

It can be written as a sum of positive squares in 2 ways, for example, as 21022225 + 299209 = 4585^2 + 547^2 .

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21321431) 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, 313517 + ... + 313584.

Almost surely, 2^21321434 is an apocalyptic number.

21321434 is a deficient number, since it is larger than the sum of its proper divisors (12542074).

21321434 is a wasteful number, since it uses less digits than its factorization.

21321434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 627120.

The product of its digits is 576, while the sum is 20.

The square root of 21321434 is about 4617.5138332224. The cubic root of 21321434 is about 277.2929342940.

Adding to 21321434 its reverse (43412312), we get a palindrome (64733746).

The spelling of 21321434 in words is "twenty-one million, three hundred twenty-one thousand, four hundred thirty-four".