21031321443 has 8 divisors (see below), whose sum is σ = 30591013056. Its totient is φ = 12746255400.

The previous prime is 21031321397. The next prime is 21031321447. The reversal of 21031321443 is 34412313012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21031321443 - 2⁹ = 21031320931 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21031321447) 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 7 ways as a sum of consecutive naturals, for example, 318656353 + ... + 318656418.

It is an arithmetic number, because the mean of its divisors is an integer number (3823876632).

Almost surely, 2^21031321443 is an apocalyptic number.

21031321443 is a deficient number, since it is larger than the sum of its proper divisors (9559691613).

21031321443 is a wasteful number, since it uses less digits than its factorization.

21031321443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 637312785.

The product of its (nonzero) digits is 1728, while the sum is 24.

Adding to 21031321443 its reverse (34412313012), we get a palindrome (55443634455).

The spelling of 21031321443 in words is "twenty-one billion, thirty-one million, three hundred twenty-one thousand, four hundred forty-three".