20421541 has 8 divisors (see below), whose sum is σ = 23393024. Its totient is φ = 17463600.

The previous prime is 20421503. The next prime is 20421553. The reversal of 20421541 is 14512402.

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

It is not a de Polignac number, because 20421541 - 2⁷ = 20421413 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 (20421571) 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, 91 + ... + 6391.

It is an arithmetic number, because the mean of its divisors is an integer number (2924128).

Almost surely, 2^20421541 is an apocalyptic number.

It is an amenable number.

20421541 is a deficient number, since it is larger than the sum of its proper divisors (2971483).

20421541 is an equidigital number, since it uses as much as digits as its factorization.

20421541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6771.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 20421541 is about 4519.0199158667. The cubic root of 20421541 is about 273.3355818111.

Adding to 20421541 its reverse (14512402), we get a palindrome (34933943).

The spelling of 20421541 in words is "twenty million, four hundred twenty-one thousand, five hundred forty-one".