20605225 has 24 divisors (see below), whose sum is σ = 26795160. Its totient is φ = 15697920.

The previous prime is 20605201. The next prime is 20605229. The reversal of 20605225 is 52250602.

It can be written as a sum of positive squares in 12 ways, for example, as 1490841 + 19114384 = 1221^2 + 4372^2 .

It is not a de Polignac number, because 20605225 - 2⁹ = 20604713 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20605196 and 20605205.

It is not an unprimeable number, because it can be changed into a prime (20605229) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 70179 + ... + 70471.

It is an arithmetic number, because the mean of its divisors is an integer number (1116465).

Almost surely, 2^20605225 is an apocalyptic number.

20605225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20605225 is a deficient number, since it is larger than the sum of its proper divisors (6189935).

20605225 is a wasteful number, since it uses less digits than its factorization.

20605225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429 (or 424 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 20605225 is about 4539.2978531927. The cubic root of 20605225 is about 274.1526534947.

Adding to 20605225 its reverse (52250602), we get a palindrome (72855827).

The spelling of 20605225 in words is "twenty million, six hundred five thousand, two hundred twenty-five".