19648636478640 has 480 divisors, whose sum is σ = 71640988683264. Its totient is φ = 4797257287680.

The previous prime is 19648636478599. The next prime is 19648636478659. The reversal of 19648636478640 is 4687463684691.

19648636478640 is a `hidden beast` number, since 1 + 9 + 6 + 4 + 86 + 36 + 478 + 6 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4442375469 + ... + 4442379891.

Almost surely, 2^{19648636478640} is an apocalyptic number.

19648636478640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19648636478640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35820494341632).

19648636478640 is an abundant number, since it is smaller than the sum of its proper divisors (51992352204624).

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

19648636478640 is a wasteful number, since it uses less digits than its factorization.

19648636478640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8209 (or 8200 counting only the distinct ones).

The product of its (nonzero) digits is 1003290624, while the sum is 72.

The spelling of 19648636478640 in words is "nineteen trillion, six hundred forty-eight billion, six hundred thirty-six million, four hundred seventy-eight thousand, six hundred forty".