20503911 has 4 divisors (see below), whose sum is σ = 27338552. Its totient is φ = 13669272.

The previous prime is 20503871. The next prime is 20503937. The reversal of 20503911 is 11930502.

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

It is not a de Polignac number, because 20503911 - 2¹⁰ = 20502887 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 (20503961) 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, 3417316 + ... + 3417321.

It is an arithmetic number, because the mean of its divisors is an integer number (6834638).

Almost surely, 2^20503911 is an apocalyptic number.

20503911 is a deficient number, since it is larger than the sum of its proper divisors (6834641).

20503911 is an equidigital number, since it uses as much as digits as its factorization.

20503911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6834640.

The product of its (nonzero) digits is 270, while the sum is 21.

The square root of 20503911 is about 4528.1244461697. The cubic root of 20503911 is about 273.7025872308.

The spelling of 20503911 in words is "twenty million, five hundred three thousand, nine hundred eleven".