21000430133 has 4 divisors (see below), whose sum is σ = 21512635788. Its totient is φ = 20488224480.

The previous prime is 21000430111. The next prime is 21000430159. The reversal of 21000430133 is 33103400012.

It is a happy number.

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 5037876484 + 15962553649 = 70978^2 + 126343^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000430133 - 2²⁴ = 20983652917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000430933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 256102766 + ... + 256102847.

It is an arithmetic number, because the mean of its divisors is an integer number (5378158947).

Almost surely, 2^21000430133 is an apocalyptic number.

It is an amenable number.

21000430133 is a deficient number, since it is larger than the sum of its proper divisors (512205655).

21000430133 is an equidigital number, since it uses as much as digits as its factorization.

21000430133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 512205654.

The product of its (nonzero) digits is 216, while the sum is 17.

Adding to 21000430133 its reverse (33103400012), we get a palindrome (54103830145).

The spelling of 21000430133 in words is "twenty-one billion, four hundred thirty thousand, one hundred thirty-three".