21538663348 has 12 divisors (see below), whose sum is σ = 37693990180. Its totient is φ = 10768951872.

The previous prime is 21538663343. The next prime is 21538663379. The reversal of 21538663348 is 84336683512.

It can be written as a sum of positive squares in 2 ways, for example, as 4807758244 + 16730905104 = 69338^2 + 129348^2 .

It is a hoax number, since the sum of its digits (49) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21538663343) 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 3 ways as a sum of consecutive naturals, for example, 61168 + ... + 216376.

Almost surely, 2^21538663348 is an apocalyptic number.

It is an amenable number.

21538663348 is a deficient number, since it is larger than the sum of its proper divisors (16155326832).

21538663348 is a wasteful number, since it uses less digits than its factorization.

21538663348 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189906 (or 189904 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 49.

The spelling of 21538663348 in words is "twenty-one billion, five hundred thirty-eight million, six hundred sixty-three thousand, three hundred forty-eight".