21033131443 has 4 divisors (see below), whose sum is σ = 21036905728. Its totient is φ = 21029357160.

The previous prime is 21033131419. The next prime is 21033131447. The reversal of 21033131443 is 34413133012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21033131443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21033131447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1878771 + ... + 1889932.

It is an arithmetic number, because the mean of its divisors is an integer number (5259226432).

Almost surely, 2^21033131443 is an apocalyptic number.

21033131443 is a deficient number, since it is larger than the sum of its proper divisors (3774285).

21033131443 is an equidigital number, since it uses as much as digits as its factorization.

21033131443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3774284.

The product of its (nonzero) digits is 2592, while the sum is 25.

Adding to 21033131443 its reverse (34413133012), we get a palindrome (55446264455).

The spelling of 21033131443 in words is "twenty-one billion, thirty-three million, one hundred thirty-one thousand, four hundred forty-three".