20124421 has 4 divisors (see below), whose sum is σ = 20400172. Its totient is φ = 19848672.

The previous prime is 20124409. The next prime is 20124437. The reversal of 20124421 is 12442102.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11356900 + 8767521 = 3370^2 + 2961^2 .

It is a cyclic number.

It is not a de Polignac number, because 20124421 - 2⁵ = 20124389 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20124395 and 20124404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20124491) 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, 137766 + ... + 137911.

It is an arithmetic number, because the mean of its divisors is an integer number (5100043).

Almost surely, 2^20124421 is an apocalyptic number.

It is an amenable number.

20124421 is a deficient number, since it is larger than the sum of its proper divisors (275751).

20124421 is an equidigital number, since it uses as much as digits as its factorization.

20124421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275750.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 20124421 is about 4486.0250779504. The cubic root of 20124421 is about 272.0034826904.

Adding to 20124421 its reverse (12442102), we get a palindrome (32566523).

The spelling of 20124421 in words is "twenty million, one hundred twenty-four thousand, four hundred twenty-one".