20988241 has 4 divisors (see below), whose sum is σ = 20997684. Its totient is φ = 20978800.

The previous prime is 20988221. The next prime is 20988299. The reversal of 20988241 is 14288902.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 14288902 = 2 ⋅7144451.

It can be written as a sum of positive squares in 2 ways, for example, as 14592400 + 6395841 = 3820^2 + 2529^2 .

It is a cyclic number.

It is not a de Polignac number, because 20988241 - 2¹⁹ = 20463953 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20988197 and 20988206.

It is not an unprimeable number, because it can be changed into a prime (20988211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 651 + ... + 6511.

It is an arithmetic number, because the mean of its divisors is an integer number (5249421).

Almost surely, 2^20988241 is an apocalyptic number.

It is an amenable number.

20988241 is a deficient number, since it is larger than the sum of its proper divisors (9443).

20988241 is an equidigital number, since it uses as much as digits as its factorization.

20988241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9442.

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 20988241 is about 4581.2925032135. The cubic root of 20988241 is about 275.8409124847.

The spelling of 20988241 in words is "twenty million, nine hundred eighty-eight thousand, two hundred forty-one".