21435534 has 48 divisors (see below), whose sum is σ = 49280400. Its totient is φ = 6715008.

The previous prime is 21435529. The next prime is 21435551. The reversal of 21435534 is 43553412.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21435498 and 21435507.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 79552 + ... + 79820.

It is an arithmetic number, because the mean of its divisors is an integer number (1026675).

Almost surely, 2^21435534 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21435534, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24640200).

21435534 is an abundant number, since it is smaller than the sum of its proper divisors (27844866).

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

21435534 is a wasteful number, since it uses less digits than its factorization.

21435534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 529 (or 526 counting only the distinct ones).

The product of its digits is 7200, while the sum is 27.

The square root of 21435534 is about 4629.8524814512. The cubic root of 21435534 is about 277.7866917791.

Adding to 21435534 its reverse (43553412), we get a palindrome (64988946).

The spelling of 21435534 in words is "twenty-one million, four hundred thirty-five thousand, five hundred thirty-four".