21052533 has 4 divisors (see below), whose sum is σ = 28070048. Its totient is φ = 14035020.

The previous prime is 21052489. The next prime is 21052547. The reversal of 21052533 is 33525012.

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.

It is not a de Polignac number, because 21052533 - 2⁶ = 21052469 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 (21052553) 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, 3508753 + ... + 3508758.

It is an arithmetic number, because the mean of its divisors is an integer number (7017512).

Almost surely, 2^21052533 is an apocalyptic number.

It is an amenable number.

21052533 is a deficient number, since it is larger than the sum of its proper divisors (7017515).

21052533 is an equidigital number, since it uses as much as digits as its factorization.

21052533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7017514.

The product of its (nonzero) digits is 900, while the sum is 21.

The square root of 21052533 is about 4588.3039350069. The cubic root of 21052533 is about 276.1222809345.

Adding to 21052533 its reverse (33525012), we get a palindrome (54577545).

The spelling of 21052533 in words is "twenty-one million, fifty-two thousand, five hundred thirty-three".