20445503 has 4 divisors (see below), whose sum is σ = 22018248. Its totient is φ = 18872760.

The previous prime is 20445499. The next prime is 20445521. The reversal of 20445503 is 30554402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30554402 = 2 ⋅15277201.

It is a cyclic number.

It is not a de Polignac number, because 20445503 - 2² = 20445499 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 (20445533) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 786353 + ... + 786378.

It is an arithmetic number, because the mean of its divisors is an integer number (5504562).

Almost surely, 2^20445503 is an apocalyptic number.

20445503 is a deficient number, since it is larger than the sum of its proper divisors (1572745).

20445503 is a wasteful number, since it uses less digits than its factorization.

20445503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1572744.

The product of its (nonzero) digits is 2400, while the sum is 23.

The square root of 20445503 is about 4521.6703771947. The cubic root of 20445503 is about 273.4424478430.

Adding to 20445503 its reverse (30554402), we get a palindrome (50999905).

The spelling of 20445503 in words is "twenty million, four hundred forty-five thousand, five hundred three".