20415445 has 4 divisors (see below), whose sum is σ = 24498540. Its totient is φ = 16332352.

The previous prime is 20415431. The next prime is 20415457. The reversal of 20415445 is 54451402.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54451402 = 2 ⋅27225701.

It can be written as a sum of positive squares in 2 ways, for example, as 2792241 + 17623204 = 1671^2 + 4198^2 .

It is a cyclic number.

It is not a de Polignac number, because 20415445 - 2¹⁷ = 20284373 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2041540 + ... + 2041549.

It is an arithmetic number, because the mean of its divisors is an integer number (6124635).

Almost surely, 2^20415445 is an apocalyptic number.

It is an amenable number.

20415445 is a deficient number, since it is larger than the sum of its proper divisors (4083095).

20415445 is an equidigital number, since it uses as much as digits as its factorization.

20415445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4083094.

The product of its (nonzero) digits is 3200, while the sum is 25.

The square root of 20415445 is about 4518.3453829914. The cubic root of 20415445 is about 273.3083814555.

Adding to 20415445 its reverse (54451402), we get a palindrome (74866847).

The spelling of 20415445 in words is "twenty million, four hundred fifteen thousand, four hundred forty-five".