20030905 has 16 divisors (see below), whose sum is σ = 24799104. Its totient is φ = 15523200.

The previous prime is 20030893. The next prime is 20030939. The reversal of 20030905 is 50903002.

20030905 = 140² + 141² + ... + 397².

It is not a de Polignac number, because 20030905 - 2¹⁷ = 19899833 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 32157 + ... + 32773.

It is an arithmetic number, because the mean of its divisors is an integer number (1549944).

Almost surely, 2^20030905 is an apocalyptic number.

It is an amenable number.

20030905 is a deficient number, since it is larger than the sum of its proper divisors (4768199).

20030905 is a wasteful number, since it uses less digits than its factorization.

20030905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 816.

The product of its (nonzero) digits is 270, while the sum is 19.

The square root of 20030905 is about 4475.5899052527. The cubic root of 20030905 is about 271.5815048322.

Adding to 20030905 its reverse (50903002), we get a palindrome (70933907).

The spelling of 20030905 in words is "twenty million, thirty thousand, nine hundred five".