19987765683648 has 56 divisors (see below), whose sum is σ = 60439196237952. Its totient is φ = 5710790194944.

The previous prime is 19987765683643. The next prime is 19987765683709. The reversal of 19987765683648 is 84638656778991.

It is a tau number, because it is divible by the number of its divisors (56).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19987765683643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7435923390 + ... + 7435926077.

It is an arithmetic number, because the mean of its divisors is an integer number (1079271361392).

Almost surely, 2^{19987765683648} is an apocalyptic number.

It is an amenable number.

19987765683648 is an abundant number, since it is smaller than the sum of its proper divisors (40451430554304).

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

19987765683648 is a wasteful number, since it uses less digits than its factorization.

19987765683648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14871849489 (or 14871849479 counting only the distinct ones).

The product of its digits is 26336378880, while the sum is 87.

The spelling of 19987765683648 in words is "nineteen trillion, nine hundred eighty-seven billion, seven hundred sixty-five million, six hundred eighty-three thousand, six hundred forty-eight".