19955717663616 has 896 divisors, whose sum is σ = 72692082796800. Its totient is φ = 5327311970304.

The previous prime is 19955717663587. The next prime is 19955717663633. The reversal of 19955717663616 is 61636671755991.

19955717663616 is a `hidden beast` number, since 1 + 9 + 9 + 5 + 571 + 7 + 6 + 6 + 36 + 16 = 666.

It is a tau number, because it is divible by the number of its divisors (896).

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 an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 905955195 + ... + 905977221.

Almost surely, 2^{19955717663616} is an apocalyptic number.

19955717663616 is a gapful number since it is divisible by the number (16) 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 19955717663616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36346041398400).

19955717663616 is an abundant number, since it is smaller than the sum of its proper divisors (52736365133184).

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

19955717663616 is an equidigital number, since it uses as much as digits as its factorization.

19955717663616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22158 (or 22131 counting only the distinct ones).

The product of its digits is 385786800, while the sum is 72.

The spelling of 19955717663616 in words is "nineteen trillion, nine hundred fifty-five billion, seven hundred seventeen million, six hundred sixty-three thousand, six hundred sixteen".