21254442 has 16 divisors (see below), whose sum is σ = 46373472. Its totient is φ = 6440720.

The previous prime is 21254417. The next prime is 21254447. The reversal of 21254442 is 24445212.

It is a happy number.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21254447) 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, 160953 + ... + 161084.

It is an arithmetic number, because the mean of its divisors is an integer number (2898342).

Almost surely, 2^21254442 is an apocalyptic number.

21254442 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21254442 is an abundant number, since it is smaller than the sum of its proper divisors (25119030).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21254442 is a wasteful number, since it uses less digits than its factorization.

21254442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322053.

The product of its digits is 2560, while the sum is 24.

The square root of 21254442 is about 4610.2540060175. The cubic root of 21254442 is about 277.0022112280.

Adding to 21254442 its reverse (24445212), we get a palindrome (45699654).

The spelling of 21254442 in words is "twenty-one million, two hundred fifty-four thousand, four hundred forty-two".