21230441 has 4 divisors (see below), whose sum is σ = 21297732. Its totient is φ = 21163152.

The previous prime is 21230431. The next prime is 21230459. The reversal of 21230441 is 14403212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2706025 + 18524416 = 1645^2 + 4304^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21230441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21230401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33170 + ... + 33803.

It is an arithmetic number, because the mean of its divisors is an integer number (5324433).

Almost surely, 2^21230441 is an apocalyptic number.

It is an amenable number.

21230441 is a deficient number, since it is larger than the sum of its proper divisors (67291).

21230441 is an equidigital number, since it uses as much as digits as its factorization.

21230441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67290.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21230441 is about 4607.6502688464. The cubic root of 21230441 is about 276.8979062216.

Adding to 21230441 its reverse (14403212), we get a palindrome (35633653).

The spelling of 21230441 in words is "twenty-one million, two hundred thirty thousand, four hundred forty-one".