20780225 has 12 divisors (see below), whose sum is σ = 25881900. Its totient is φ = 16550400.

The previous prime is 20780219. The next prime is 20780237. The reversal of 20780225 is 52208702.

It can be written as a sum of positive squares in 6 ways, for example, as 2666689 + 18113536 = 1633^2 + 4256^2 .

It is not a de Polignac number, because 20780225 - 2¹⁶ = 20714689 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20780194 and 20780203.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4301 + ... + 7749.

It is an arithmetic number, because the mean of its divisors is an integer number (2156825).

Almost surely, 2^20780225 is an apocalyptic number.

20780225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20780225 is a deficient number, since it is larger than the sum of its proper divisors (5101675).

20780225 is a wasteful number, since it uses less digits than its factorization.

20780225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3700 (or 3695 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 26.

The square root of 20780225 is about 4558.5332070744. The cubic root of 20780225 is about 274.9265919766.

Adding to 20780225 its reverse (52208702), we get a palindrome (72988927).

The spelling of 20780225 in words is "twenty million, seven hundred eighty thousand, two hundred twenty-five".