20503121 has 8 divisors (see below), whose sum is σ = 21228288. Its totient is φ = 19782000.

The previous prime is 20503117. The next prime is 20503129. The reversal of 20503121 is 12130502.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20503121 - 2² = 20503117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20503096 and 20503105.

It is not an unprimeable number, because it can be changed into a prime (20503129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12266 + ... + 13836.

It is an arithmetic number, because the mean of its divisors is an integer number (2653536).

Almost surely, 2^20503121 is an apocalyptic number.

It is an amenable number.

20503121 is a deficient number, since it is larger than the sum of its proper divisors (725167).

20503121 is a wasteful number, since it uses less digits than its factorization.

20503121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2023.

The product of its (nonzero) digits is 60, while the sum is 14.

The square root of 20503121 is about 4528.0372127446. The cubic root of 20503121 is about 273.6990720019.

Adding to 20503121 its reverse (12130502), we get a palindrome (32633623).

The spelling of 20503121 in words is "twenty million, five hundred three thousand, one hundred twenty-one".