21430541 has 4 divisors (see below), whose sum is σ = 23378784. Its totient is φ = 19482300.

The previous prime is 21430531. The next prime is 21430559. The reversal of 21430541 is 14503412.

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 21430541 - 2⁶ = 21430477 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21430531) 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, 974105 + ... + 974126.

It is an arithmetic number, because the mean of its divisors is an integer number (5844696).

Almost surely, 2^21430541 is an apocalyptic number.

It is an amenable number.

21430541 is a deficient number, since it is larger than the sum of its proper divisors (1948243).

21430541 is a wasteful number, since it uses less digits than its factorization.

21430541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1948242.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 21430541 is about 4629.3132320032. The cubic root of 21430541 is about 277.7651217286.

Adding to 21430541 its reverse (14503412), we get a palindrome (35933953).

The spelling of 21430541 in words is "twenty-one million, four hundred thirty thousand, five hundred forty-one".