21122441 has 6 divisors (see below), whose sum is σ = 22081290. Its totient is φ = 20203568.

The previous prime is 21122419. The next prime is 21122443. The reversal of 21122441 is 14422112.

It can be written as a sum of positive squares in only one way, i.e., 15832441 + 5290000 = 3979^2 + 2300^2 .

It is not a de Polignac number, because 21122441 - 2¹⁰ = 21121417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21122443) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 19436 + ... + 20493.

It is an arithmetic number, because the mean of its divisors is an integer number (3680215).

Almost surely, 2^21122441 is an apocalyptic number.

It is an amenable number.

21122441 is a deficient number, since it is larger than the sum of its proper divisors (958849).

21122441 is an equidigital number, since it uses as much as digits as its factorization.

21122441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39975 (or 39952 counting only the distinct ones).

The product of its digits is 128, while the sum is 17.

The square root of 21122441 is about 4595.9156867810. The cubic root of 21122441 is about 276.4275779967.

Adding to 21122441 its reverse (14422112), we get a palindrome (35544553).

The spelling of 21122441 in words is "twenty-one million, one hundred twenty-two thousand, four hundred forty-one".