21534133 has 4 divisors (see below), whose sum is σ = 21544480. Its totient is φ = 21523788.

The previous prime is 21534089. The next prime is 21534151. The reversal of 21534133 is 33143512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21534133 - 2¹⁷ = 21403061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21534533) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 843 + ... + 6616.

It is an arithmetic number, because the mean of its divisors is an integer number (5386120).

Almost surely, 2^21534133 is an apocalyptic number.

It is an amenable number.

21534133 is a deficient number, since it is larger than the sum of its proper divisors (10347).

21534133 is an equidigital number, since it uses as much as digits as its factorization.

21534133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10346.

The product of its digits is 1080, while the sum is 22.

The square root of 21534133 is about 4640.4884441188. The cubic root of 21534133 is about 278.2119607382.

Adding to 21534133 its reverse (33143512), we get a palindrome (54677645).

The spelling of 21534133 in words is "twenty-one million, five hundred thirty-four thousand, one hundred thirty-three".