20130421 has 4 divisors (see below), whose sum is σ = 20203372. Its totient is φ = 20057472.

The previous prime is 20130413. The next prime is 20130449. The reversal of 20130421 is 12403102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12403102 = 2 ⋅6201551.

It can be written as a sum of positive squares in 2 ways, for example, as 6180196 + 13950225 = 2486^2 + 3735^2 .

It is a cyclic number.

It is not a de Polignac number, because 20130421 - 2³ = 20130413 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 (20130491) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 36060 + ... + 36613.

It is an arithmetic number, because the mean of its divisors is an integer number (5050843).

Almost surely, 2^20130421 is an apocalyptic number.

It is an amenable number.

20130421 is a deficient number, since it is larger than the sum of its proper divisors (72951).

20130421 is an equidigital number, since it uses as much as digits as its factorization.

20130421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72950.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 20130421 is about 4486.6937715873. The cubic root of 20130421 is about 272.0305121841.

Adding to 20130421 its reverse (12403102), we get a palindrome (32533523).

The spelling of 20130421 in words is "twenty million, one hundred thirty thousand, four hundred twenty-one".