21241305 has 32 divisors (see below), whose sum is σ = 39409920. Its totient is φ = 10834560.

The previous prime is 21241271. The next prime is 21241327. The reversal of 21241305 is 50314212.

It is not a de Polignac number, because 21241305 - 2⁸ = 21241049 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 316 + ... + 6525.

It is an arithmetic number, because the mean of its divisors is an integer number (1231560).

Almost surely, 2^21241305 is an apocalyptic number.

It is an amenable number.

21241305 is a deficient number, since it is larger than the sum of its proper divisors (18168615).

21241305 is a wasteful number, since it uses less digits than its factorization.

21241305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6878 (or 6872 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21241305 is about 4608.8290269872. The cubic root of 21241305 is about 276.9451293870.

Adding to 21241305 its reverse (50314212), we get a palindrome (71555517).

The spelling of 21241305 in words is "twenty-one million, two hundred forty-one thousand, three hundred five".