21898788938 has 8 divisors (see below), whose sum is σ = 35374966788. Its totient is φ = 10107133344.

The previous prime is 21898788893. The next prime is 21898788971. The reversal of 21898788938 is 83988789812.

It can be written as a sum of positive squares in 2 ways, for example, as 21250933729 + 647855209 = 145777^2 + 25453^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 421130531 + ... + 421130582.

Almost surely, 2^21898788938 is an apocalyptic number.

21898788938 is a deficient number, since it is larger than the sum of its proper divisors (13476177850).

21898788938 is a wasteful number, since it uses less digits than its factorization.

21898788938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 842261128.

The product of its digits is 111476736, while the sum is 71.

The spelling of 21898788938 in words is "twenty-one billion, eight hundred ninety-eight million, seven hundred eighty-eight thousand, nine hundred thirty-eight".