21241345 has 16 divisors (see below), whose sum is σ = 26095680. Its totient is φ = 16593984.

The previous prime is 21241343. The next prime is 21241361. The reversal of 21241345 is 54314212.

It is a cyclic number.

It is not a de Polignac number, because 21241345 - 2¹ = 21241343 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21241343) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54411 + ... + 54799.

It is an arithmetic number, because the mean of its divisors is an integer number (1630980).

Almost surely, 2^21241345 is an apocalyptic number.

It is an amenable number.

21241345 is a deficient number, since it is larger than the sum of its proper divisors (4854335).

21241345 is a wasteful number, since it uses less digits than its factorization.

21241345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 624.

The product of its digits is 960, while the sum is 22.

The square root of 21241345 is about 4608.8333664822. The cubic root of 21241345 is about 276.9453032275.

Adding to 21241345 its reverse (54314212), we get a palindrome (75555557).

The spelling of 21241345 in words is "twenty-one million, two hundred forty-one thousand, three hundred forty-five".