20178225 has 18 divisors (see below), whose sum is σ = 36141846. Its totient is φ = 10761600.

The previous prime is 20178187. The next prime is 20178239. The reversal of 20178225 is 52287102.

It can be written as a sum of positive squares in 3 ways, for example, as 2005056 + 18173169 = 1416^2 + 4263^2 .

It is not a de Polignac number, because 20178225 - 2⁷ = 20178097 is a prime.

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 17 ways as a sum of consecutive naturals, for example, 44616 + ... + 45065.

Almost surely, 2^20178225 is an apocalyptic number.

20178225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20178225 is a deficient number, since it is larger than the sum of its proper divisors (15963621).

20178225 is a wasteful number, since it uses less digits than its factorization.

20178225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89697 (or 89689 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 20178225 is about 4492.0179207122. The cubic root of 20178225 is about 272.2456735469.

The spelling of 20178225 in words is "twenty million, one hundred seventy-eight thousand, two hundred twenty-five".