21133225 has 12 divisors (see below), whose sum is σ = 27585040. Its totient is φ = 16016400.

The previous prime is 21133219. The next prime is 21133237. The reversal of 21133225 is 52233112.

It is not a de Polignac number, because 21133225 - 2²³ = 12744617 is a prime.

It is a super-2 number, since 2×21133225² = 893226397801250, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 21771 + ... + 22720.

Almost surely, 2^21133225 is an apocalyptic number.

21133225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21133225 is a deficient number, since it is larger than the sum of its proper divisors (6451815).

21133225 is a wasteful number, since it uses less digits than its factorization.

21133225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44520 (or 44515 counting only the distinct ones).

The product of its digits is 360, while the sum is 19.

The square root of 21133225 is about 4597.0887526782. The cubic root of 21133225 is about 276.4746130882.

Adding to 21133225 its reverse (52233112), we get a palindrome (73366337).

The spelling of 21133225 in words is "twenty-one million, one hundred thirty-three thousand, two hundred twenty-five".