21064443398 has 4 divisors (see below), whose sum is σ = 31596665100. Its totient is φ = 10532221698.

The previous prime is 21064443391. The next prime is 21064443403. The reversal of 21064443398 is 89334446012.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21064443391) 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 as a sum of consecutive naturals, namely, 5266110848 + ... + 5266110851.

It is an arithmetic number, because the mean of its divisors is an integer number (7899166275).

Almost surely, 2^21064443398 is an apocalyptic number.

21064443398 is a deficient number, since it is larger than the sum of its proper divisors (10532221702).

21064443398 is a wasteful number, since it uses less digits than its factorization.

21064443398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10532221701.

The product of its (nonzero) digits is 497664, while the sum is 44.

The spelling of 21064443398 in words is "twenty-one billion, sixty-four million, four hundred forty-three thousand, three hundred ninety-eight".