21243430033 has 4 divisors (see below), whose sum is σ = 24278205760. Its totient is φ = 18208654308.

The previous prime is 21243429931. The next prime is 21243430067. The reversal of 21243430033 is 33003434212.

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 21243430033 - 2²¹ = 21241332881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21243430093) 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, 1517387853 + ... + 1517387866.

It is an arithmetic number, because the mean of its divisors is an integer number (6069551440).

Almost surely, 2^21243430033 is an apocalyptic number.

It is an amenable number.

21243430033 is a deficient number, since it is larger than the sum of its proper divisors (3034775727).

21243430033 is an equidigital number, since it uses as much as digits as its factorization.

21243430033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3034775726.

The product of its (nonzero) digits is 5184, while the sum is 25.

Adding to 21243430033 its reverse (33003434212), we get a palindrome (54246864245).

The spelling of 21243430033 in words is "twenty-one billion, two hundred forty-three million, four hundred thirty thousand, thirty-three".