21193538553838 has 16 divisors (see below), whose sum is σ = 36791676334080. Its totient is φ = 8967971105496.

The previous prime is 21193538553827. The next prime is 21193538553857. The reversal of 21193538553838 is 83835583539112.

It is a self number, because there is not a number n which added to its sum of digits gives 21193538553838.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9581164606 + ... + 9581166817.

It is an arithmetic number, because the mean of its divisors is an integer number (2299479770880).

Almost surely, 2^{21193538553838} is an apocalyptic number.

21193538553838 is a deficient number, since it is larger than the sum of its proper divisors (15598137780242).

21193538553838 is a wasteful number, since it uses less digits than its factorization.

21193538553838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19162331511.

The product of its digits is 93312000, while the sum is 64.

The spelling of 21193538553838 in words is "twenty-one trillion, one hundred ninety-three billion, five hundred thirty-eight million, five hundred fifty-three thousand, eight hundred thirty-eight".