21915626338 has 4 divisors (see below), whose sum is σ = 32873439510. Its totient is φ = 10957813168.

The previous prime is 21915626321. The next prime is 21915626339. The reversal of 21915626338 is 83362651912.

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., 18269036569 + 3646589769 = 135163^2 + 60387^2 .

It is not an unprimeable number, because it can be changed into a prime (21915626339) 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, 5478906583 + ... + 5478906586.

Almost surely, 2^21915626338 is an apocalyptic number.

21915626338 is a deficient number, since it is larger than the sum of its proper divisors (10957813172).

21915626338 is a wasteful number, since it uses less digits than its factorization.

21915626338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10957813171.

The product of its digits is 466560, while the sum is 46.

The spelling of 21915626338 in words is "twenty-one billion, nine hundred fifteen million, six hundred twenty-six thousand, three hundred thirty-eight".