21042153 has 16 divisors (see below), whose sum is σ = 34008000. Its totient is φ = 12752640.

The previous prime is 21042127. The next prime is 21042157. The reversal of 21042153 is 35124012.

It is not a de Polignac number, because 21042153 - 2⁶ = 21042089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21042157) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 35128 + ... + 35721.

It is an arithmetic number, because the mean of its divisors is an integer number (2125500).

Almost surely, 2^21042153 is an apocalyptic number.

It is an amenable number.

21042153 is a deficient number, since it is larger than the sum of its proper divisors (12965847).

21042153 is a wasteful number, since it uses less digits than its factorization.

21042153 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70869 (or 70863 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21042153 is about 4587.1726586210. The cubic root of 21042153 is about 276.0768925647.

Adding to 21042153 its reverse (35124012), we get a palindrome (56166165).

The spelling of 21042153 in words is "twenty-one million, forty-two thousand, one hundred fifty-three".