19905374863936 has 21 divisors (see below), whose sum is σ = 39499799072761. Its totient is φ = 9952669585792.

The previous prime is 19905374863909. The next prime is 19905374863939. The reversal of 19905374863936 is 63936847350991.

The square root of 19905374863936 is 4461544.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 9013685198400 + 10891689665536 = 3002280^2 + 3300256^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19905374863939) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 35413506 + ... + 35971198.

Almost surely, 2^{19905374863936} is an apocalyptic number.

19905374863936 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

19905374863936 is the 4461544-th square number.

It is an amenable number.

19905374863936 is a deficient number, since it is larger than the sum of its proper divisors (19594424208825).

19905374863936 is an frugal number, since it uses more digits than its factorization.

19905374863936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1115398 (or 557695 counting only the distinct ones).

The product of its (nonzero) digits is 793618560, while the sum is 73.

The spelling of 19905374863936 in words is "nineteen trillion, nine hundred five billion, three hundred seventy-four million, eight hundred sixty-three thousand, nine hundred thirty-six".