21230225 has 12 divisors (see below), whose sum is σ = 26688396. Its totient is φ = 16750080.

The previous prime is 21230213. The next prime is 21230227. The reversal of 21230225 is 52203212.

It can be written as a sum of positive squares in 6 ways, for example, as 5776 + 21224449 = 76^2 + 4607^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21230225 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21230227) 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, 3992 + ... + 7641.

It is an arithmetic number, because the mean of its divisors is an integer number (2224033).

Almost surely, 2^21230225 is an apocalyptic number.

21230225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21230225 is a deficient number, since it is larger than the sum of its proper divisors (5458171).

21230225 is a wasteful number, since it uses less digits than its factorization.

21230225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11716 (or 11711 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 21230225 is about 4607.6268295078. The cubic root of 21230225 is about 276.8969671588.

Adding to 21230225 its reverse (52203212), we get a palindrome (73433437).

The spelling of 21230225 in words is "twenty-one million, two hundred thirty thousand, two hundred twenty-five".