21402441 has 16 divisors (see below), whose sum is σ = 31830720. Its totient is φ = 14212800.

The previous prime is 21402419. The next prime is 21402467. The reversal of 21402441 is 14420412.

It is not a de Polignac number, because 21402441 - 2¹⁰ = 21401417 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21402401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6241 + ... + 9041.

It is an arithmetic number, because the mean of its divisors is an integer number (1989420).

Almost surely, 2^21402441 is an apocalyptic number.

It is an amenable number.

21402441 is a deficient number, since it is larger than the sum of its proper divisors (10428279).

21402441 is a wasteful number, since it uses less digits than its factorization.

21402441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3093 (or 3087 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 21402441 is about 4626.2772290471. The cubic root of 21402441 is about 277.6436655657.

Adding to 21402441 its reverse (14420412), we get a palindrome (35822853).

The spelling of 21402441 in words is "twenty-one million, four hundred two thousand, four hundred forty-one".