20905003 has 4 divisors (see below), whose sum is σ = 23891440. Its totient is φ = 17918568.

The previous prime is 20904979. The next prime is 20905007. The reversal of 20905003 is 30050902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20905003 - 2⁵ = 20904971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20905007) 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, 1493208 + ... + 1493221.

It is an arithmetic number, because the mean of its divisors is an integer number (5972860).

Almost surely, 2^20905003 is an apocalyptic number.

20905003 is a deficient number, since it is larger than the sum of its proper divisors (2986437).

20905003 is an equidigital number, since it uses as much as digits as its factorization.

20905003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2986436.

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

The square root of 20905003 is about 4572.1989239315. The cubic root of 20905003 is about 275.4757736412.

Adding to 20905003 its reverse (30050902), we get a palindrome (50955905).

The spelling of 20905003 in words is "twenty million, nine hundred five thousand, three".