21430441 has 4 divisors (see below), whose sum is σ = 21448192. Its totient is φ = 21412692.

The previous prime is 21430439. The next prime is 21430447. The reversal of 21430441 is 14403412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21430441 - 2¹ = 21430439 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21430447) 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, 6921 + ... + 9526.

It is an arithmetic number, because the mean of its divisors is an integer number (5362048).

Almost surely, 2^21430441 is an apocalyptic number.

It is an amenable number.

21430441 is a deficient number, since it is larger than the sum of its proper divisors (17751).

21430441 is a wasteful number, since it uses less digits than its factorization.

21430441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17750.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 21430441 is about 4629.3024312525. The cubic root of 21430441 is about 277.7646896885.

Adding to 21430441 its reverse (14403412), we get a palindrome (35833853).

The spelling of 21430441 in words is "twenty-one million, four hundred thirty thousand, four hundred forty-one".