21242133 has 48 divisors (see below), whose sum is σ = 36840960. Its totient is φ = 11642400.

The previous prime is 21242131. The next prime is 21242153. The reversal of 21242133 is 33124212.

21242133 is a `hidden beast` number, since 212 + 421 + 33 = 666.

It is not a de Polignac number, because 21242133 - 2¹ = 21242131 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21242131) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 43018 + ... + 43508.

It is an arithmetic number, because the mean of its divisors is an integer number (767520).

Almost surely, 2^21242133 is an apocalyptic number.

21242133 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21242133 is a deficient number, since it is larger than the sum of its proper divisors (15598827).

21242133 is a wasteful number, since it uses less digits than its factorization.

21242133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550 (or 547 counting only the distinct ones).

The product of its digits is 288, while the sum is 18.

The square root of 21242133 is about 4608.9188537009. The cubic root of 21242133 is about 276.9487278412.

Adding to 21242133 its reverse (33124212), we get a palindrome (54366345).

The spelling of 21242133 in words is "twenty-one million, two hundred forty-two thousand, one hundred thirty-three".