21542133 has 8 divisors (see below), whose sum is σ = 28889568. Its totient is φ = 14278064.

The previous prime is 21542119. The next prime is 21542153. The reversal of 21542133 is 33124512.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21542133 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21542153) 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 7 ways as a sum of consecutive naturals, for example, 20235 + ... + 21272.

It is an arithmetic number, because the mean of its divisors is an integer number (3611196).

Almost surely, 2^21542133 is an apocalyptic number.

It is an amenable number.

21542133 is a deficient number, since it is larger than the sum of its proper divisors (7347435).

21542133 is a wasteful number, since it uses less digits than its factorization.

21542133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41683.

The product of its digits is 720, while the sum is 21.

The square root of 21542133 is about 4641.3503423034. The cubic root of 21542133 is about 278.2464086868.

Adding to 21542133 its reverse (33124512), we get a palindrome (54666645).

The spelling of 21542133 in words is "twenty-one million, five hundred forty-two thousand, one hundred thirty-three".