20578228 has 72 divisors (see below), whose sum is σ = 43637832. Its totient is φ = 8448000.

The previous prime is 20578199. The next prime is 20578237. The reversal of 20578228 is 82287502.

It can be written as a sum of positive squares in 4 ways, for example, as 39204 + 20539024 = 198^2 + 4532^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 20578193 and 20578202.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 337318 + ... + 337378.

It is an arithmetic number, because the mean of its divisors is an integer number (606081).

Almost surely, 2^20578228 is an apocalyptic number.

It is an amenable number.

20578228 is an abundant number, since it is smaller than the sum of its proper divisors (23059604).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20578228 is a wasteful number, since it uses less digits than its factorization.

20578228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 34.

The square root of 20578228 is about 4536.3231807269. The cubic root of 20578228 is about 274.0328694118.

It can be divided in two parts, 2057 and 8228, that multiplied together give a square (16924996 = 4114²).

The spelling of 20578228 in words is "twenty million, five hundred seventy-eight thousand, two hundred twenty-eight".