19788497856 has 112 divisors (see below), whose sum is σ = 60703968000. Its totient is φ = 6309363456.

The previous prime is 19788497851. The next prime is 19788497867. The reversal of 19788497856 is 65879488791.

19788497856 is a `hidden beast` number, since 1 + 9 + 7 + 88 + 497 + 8 + 56 = 666.

It is a Smith number, since the sum of its digits (72) coincides with the sum of the digits of its prime factors.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19788497851) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 209206 + ... + 288693.

Almost surely, 2^19788497856 is an apocalyptic number.

19788497856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

19788497856 is an abundant number, since it is smaller than the sum of its proper divisors (40915470144).

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

19788497856 is a wasteful number, since it uses less digits than its factorization.

19788497856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497943 (or 497927 counting only the distinct ones).

The product of its digits is 243855360, while the sum is 72.

The spelling of 19788497856 in words is "nineteen billion, seven hundred eighty-eight million, four hundred ninety-seven thousand, eight hundred fifty-six".