20138445 has 12 divisors (see below), whose sum is σ = 34906716. Its totient is φ = 10740480.

The previous prime is 20138431. The next prime is 20138449. The reversal of 20138445 is 54483102.

It can be written as a sum of positive squares in 2 ways, for example, as 12404484 + 7733961 = 3522^2 + 2781^2 .

It is not a de Polignac number, because 20138445 - 2⁵ = 20138413 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20138449) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 223716 + ... + 223805.

It is an arithmetic number, because the mean of its divisors is an integer number (2908893).

Almost surely, 2^20138445 is an apocalyptic number.

It is an amenable number.

20138445 is a deficient number, since it is larger than the sum of its proper divisors (14768271).

20138445 is a wasteful number, since it uses less digits than its factorization.

20138445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 447532 (or 447529 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 20138445 is about 4487.5878821478. The cubic root of 20138445 is about 272.0666512341.

The spelling of 20138445 in words is "twenty million, one hundred thirty-eight thousand, four hundred forty-five".