21811067338 has 4 divisors (see below), whose sum is σ = 32716601010. Its totient is φ = 10905533668.

The previous prime is 21811067297. The next prime is 21811067339. The reversal of 21811067338 is 83376011812.

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

It can be written as a sum of positive squares in only one way, i.e., 16285077769 + 5525989569 = 127613^2 + 74337^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21811067338.

It is not an unprimeable number, because it can be changed into a prime (21811067339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5452766833 + ... + 5452766836.

Almost surely, 2^21811067338 is an apocalyptic number.

21811067338 is a deficient number, since it is larger than the sum of its proper divisors (10905533672).

21811067338 is a wasteful number, since it uses less digits than its factorization.

21811067338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10905533671.

The product of its (nonzero) digits is 48384, while the sum is 40.

The spelling of 21811067338 in words is "twenty-one billion, eight hundred eleven million, sixty-seven thousand, three hundred thirty-eight".