21225135 has 16 divisors (see below), whose sum is σ = 34111584. Its totient is φ = 11269632.

The previous prime is 21225121. The next prime is 21225179. The reversal of 21225135 is 53152212.

It is not a de Polignac number, because 21225135 - 2⁴ = 21225119 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 459 + ... + 6531.

It is an arithmetic number, because the mean of its divisors is an integer number (2131974).

Almost surely, 2^21225135 is an apocalyptic number.

21225135 is a deficient number, since it is larger than the sum of its proper divisors (12886449).

21225135 is a wasteful number, since it uses less digits than its factorization.

21225135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6314.

The product of its digits is 600, while the sum is 21.

The square root of 21225135 is about 4607.0744513194. The cubic root of 21225135 is about 276.8748364747.

Adding to 21225135 its reverse (53152212), we get a palindrome (74377347).

The spelling of 21225135 in words is "twenty-one million, two hundred twenty-five thousand, one hundred thirty-five".