21789869193 has 6 divisors (see below), whose sum is σ = 31474255514. Its totient is φ = 14526579456.

The previous prime is 21789869183. The next prime is 21789869201. The reversal of 21789869193 is 39196898712.

It can be written as a sum of positive squares in only one way, i.e., 20901352329 + 888516864 = 144573^2 + 29808^2 .

It is not a de Polignac number, because 21789869193 - 2⁸ = 21789868937 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21789869193.

It is not an unprimeable number, because it can be changed into a prime (21789869183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1210548280 + ... + 1210548297.

Almost surely, 2^21789869193 is an apocalyptic number.

It is an amenable number.

21789869193 is a deficient number, since it is larger than the sum of its proper divisors (9684386321).

21789869193 is a wasteful number, since it uses less digits than its factorization.

21789869193 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2421096583 (or 2421096580 counting only the distinct ones).

The product of its digits is 11757312, while the sum is 63.

The spelling of 21789869193 in words is "twenty-one billion, seven hundred eighty-nine million, eight hundred sixty-nine thousand, one hundred ninety-three".