19663933694985 has 128 divisors (see below), whose sum is σ = 35716442227200. Its totient is φ = 10262463160320.

The previous prime is 19663933694983. The next prime is 19663933694987. The reversal of 19663933694985 is 58949633936691.

It is a happy number.

19663933694985 is a `hidden beast` number, since 1 + 9 + 6 + 6 + 3 + 93 + 36 + 9 + 498 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (19663933694983) and next prime (19663933694987).

It is not a de Polignac number, because 19663933694985 - 2¹ = 19663933694983 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19663933694983) 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 127 ways as a sum of consecutive naturals, for example, 2265164845 + ... + 2265173525.

It is an arithmetic number, because the mean of its divisors is an integer number (279034704900).

Almost surely, 2^{19663933694985} is an apocalyptic number.

19663933694985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19663933694985 is a deficient number, since it is larger than the sum of its proper divisors (16052508532215).

19663933694985 is a wasteful number, since it uses less digits than its factorization.

19663933694985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10680 (or 10674 counting only the distinct ones).

The product of its digits is 6122200320, while the sum is 81.

The spelling of 19663933694985 in words is "nineteen trillion, six hundred sixty-three billion, nine hundred thirty-three million, six hundred ninety-four thousand, nine hundred eighty-five".