19966515869724 has 24 divisors (see below), whose sum is σ = 46663801242240. Its totient is φ = 6644753259504.

The previous prime is 19966515869693. The next prime is 19966515869761. The reversal of 19966515869724 is 42796851566991.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 19966515869724.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1343996064 + ... + 1344010919.

It is an arithmetic number, because the mean of its divisors is an integer number (1944325051760).

Almost surely, 2^{19966515869724} is an apocalyptic number.

It is an amenable number.

19966515869724 is an abundant number, since it is smaller than the sum of its proper divisors (26697285372516).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19966515869724 is a wasteful number, since it uses less digits than its factorization.

19966515869724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2688007609 (or 2688007607 counting only the distinct ones).

The product of its digits is 1763596800, while the sum is 78.

The spelling of 19966515869724 in words is "nineteen trillion, nine hundred sixty-six billion, five hundred fifteen million, eight hundred sixty-nine thousand, seven hundred twenty-four".