20503305 has 24 divisors (see below), whose sum is σ = 35652552. Its totient is φ = 10900224.

The previous prime is 20503279. The next prime is 20503313. The reversal of 20503305 is 50330502.

It can be written as a sum of positive squares in 4 ways, for example, as 9072144 + 11431161 = 3012^2 + 3381^2 .

It is not a de Polignac number, because 20503305 - 2⁷ = 20503177 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20067 + ... + 21063.

It is an arithmetic number, because the mean of its divisors is an integer number (1485523).

Almost surely, 2^20503305 is an apocalyptic number.

It is an amenable number.

20503305 is a deficient number, since it is larger than the sum of its proper divisors (15149247).

20503305 is a wasteful number, since it uses less digits than its factorization.

20503305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1465 (or 1462 counting only the distinct ones).

The product of its (nonzero) digits is 450, while the sum is 18.

The square root of 20503305 is about 4528.0575305533. The cubic root of 20503305 is about 273.6998907469.

Adding to 20503305 its reverse (50330502), we get a palindrome (70833807).

The spelling of 20503305 in words is "twenty million, five hundred three thousand, three hundred five".