21254225 has 12 divisors (see below), whose sum is σ = 26675376. Its totient is φ = 16796880.

The previous prime is 21254221. The next prime is 21254227. The reversal of 21254225 is 52245212.

21254225 is nontrivially palindromic in base 8.

It is not a de Polignac number, because 21254225 - 2² = 21254221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21254225.

It is not an unprimeable number, because it can be changed into a prime (21254221) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3047 + ... + 7196.

It is an arithmetic number, because the mean of its divisors is an integer number (2222948).

Almost surely, 2^21254225 is an apocalyptic number.

21254225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21254225 is a deficient number, since it is larger than the sum of its proper divisors (5421151).

21254225 is a wasteful number, since it uses less digits than its factorization.

21254225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10336 (or 10331 counting only the distinct ones).

The product of its digits is 1600, while the sum is 23.

The square root of 21254225 is about 4610.2304714624. The cubic root of 21254225 is about 277.0012685280.

Adding to 21254225 its reverse (52245212), we get a palindrome (73499437).

The spelling of 21254225 in words is "twenty-one million, two hundred fifty-four thousand, two hundred twenty-five".