20506225 has 24 divisors (see below), whose sum is σ = 27944640. Its totient is φ = 14857920.

The previous prime is 20506201. The next prime is 20506243. The reversal of 20506225 is 52260502.

It is not a de Polignac number, because 20506225 - 2⁹ = 20505713 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20506196 and 20506205.

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 23 ways as a sum of consecutive naturals, for example, 9987 + ... + 11863.

It is an arithmetic number, because the mean of its divisors is an integer number (1164360).

Almost surely, 2^20506225 is an apocalyptic number.

20506225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20506225 is a deficient number, since it is larger than the sum of its proper divisors (7438415).

20506225 is a wasteful number, since it uses less digits than its factorization.

20506225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1929 (or 1924 counting only the distinct ones).

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

The square root of 20506225 is about 4528.3799531400. The cubic root of 20506225 is about 273.7128832172.

Adding to 20506225 its reverse (52260502), we get a palindrome (72766727).

The spelling of 20506225 in words is "twenty million, five hundred six thousand, two hundred twenty-five".