20228149 has 4 divisors (see below), whose sum is σ = 20559820. Its totient is φ = 19896480.

The previous prime is 20228101. The next prime is 20228161. The reversal of 20228149 is 94182202.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5673924 + 14554225 = 2382^2 + 3815^2 .

It is a cyclic number.

It is not a de Polignac number, because 20228149 - 2¹⁹ = 19703861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20228449) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 165744 + ... + 165865.

It is an arithmetic number, because the mean of its divisors is an integer number (5139955).

Almost surely, 2^20228149 is an apocalyptic number.

It is an amenable number.

20228149 is a deficient number, since it is larger than the sum of its proper divisors (331671).

20228149 is an equidigital number, since it uses as much as digits as its factorization.

20228149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331670.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 20228149 is about 4497.5714557970. The cubic root of 20228149 is about 272.4700143758.

The spelling of 20228149 in words is "twenty million, two hundred twenty-eight thousand, one hundred forty-nine".