21210441 has 64 divisors (see below), whose sum is σ = 37324800. Its totient is φ = 10423296.

The previous prime is 21210433. The next prime is 21210461. The reversal of 21210441 is 14401212.

It is not a de Polignac number, because 21210441 - 2³ = 21210433 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21210441.

It is not an unprimeable number, because it can be changed into a prime (21210461) 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 63 ways as a sum of consecutive naturals, for example, 359470 + ... + 359528.

It is an arithmetic number, because the mean of its divisors is an integer number (583200).

Almost surely, 2^21210441 is an apocalyptic number.

21210441 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21210441 is a deficient number, since it is larger than the sum of its proper divisors (16114359).

21210441 is a wasteful number, since it uses less digits than its factorization.

21210441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158.

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 21210441 is about 4605.4794538680. The cubic root of 21210441 is about 276.8109289416.

Adding to 21210441 its reverse (14401212), we get a palindrome (35611653).

The spelling of 21210441 in words is "twenty-one million, two hundred ten thousand, four hundred forty-one".