20538421 has 8 divisors (see below), whose sum is σ = 20772864. Its totient is φ = 20305680.

The previous prime is 20538407. The next prime is 20538437. The reversal of 20538421 is 12483502.

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 20538421 - 2¹³ = 20530229 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 (20538491) 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, 55780 + ... + 56146.

It is an arithmetic number, because the mean of its divisors is an integer number (2596608).

Almost surely, 2^20538421 is an apocalyptic number.

It is an amenable number.

20538421 is a deficient number, since it is larger than the sum of its proper divisors (234443).

20538421 is a wasteful number, since it uses less digits than its factorization.

20538421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 851.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 20538421 is about 4531.9334725920. The cubic root of 20538421 is about 273.8560568466.

The spelling of 20538421 in words is "twenty million, five hundred thirty-eight thousand, four hundred twenty-one".