20603221 has 4 divisors (see below), whose sum is σ = 20613312. Its totient is φ = 20593132.

The previous prime is 20603183. The next prime is 20603243. The reversal of 20603221 is 12230602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20603221 - 2¹¹ = 20601173 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20603195 and 20603204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20603281) 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, 781 + ... + 6466.

It is an arithmetic number, because the mean of its divisors is an integer number (5153328).

Almost surely, 2^20603221 is an apocalyptic number.

It is an amenable number.

20603221 is a deficient number, since it is larger than the sum of its proper divisors (10091).

20603221 is an equidigital number, since it uses as much as digits as its factorization.

20603221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10090.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 20603221 is about 4539.0771088405. The cubic root of 20603221 is about 274.1437654622.

Adding to 20603221 its reverse (12230602), we get a palindrome (32833823).

The spelling of 20603221 in words is "twenty million, six hundred three thousand, two hundred twenty-one".