21125254 has 16 divisors (see below), whose sum is σ = 33663168. Its totient is φ = 9908352.

The previous prime is 21125239. The next prime is 21125257. The reversal of 21125254 is 45252112.

21125254 is nontrivially palindromic in base 7.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21125257) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11632 + ... + 13324.

It is an arithmetic number, because the mean of its divisors is an integer number (2103948).

Almost surely, 2^21125254 is an apocalyptic number.

21125254 is a deficient number, since it is larger than the sum of its proper divisors (12537914).

21125254 is a wasteful number, since it uses less digits than its factorization.

21125254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2079.

The product of its digits is 800, while the sum is 22.

The square root of 21125254 is about 4596.2217091868. The cubic root of 21125254 is about 276.4398486154.

Adding to 21125254 its reverse (45252112), we get a palindrome (66377366).

The spelling of 21125254 in words is "twenty-one million, one hundred twenty-five thousand, two hundred fifty-four".