163645903680 has 448 divisors, whose sum is σ = 617417510400. Its totient is φ = 36695113728.

The previous prime is 163645903679. The next prime is 163645903703. The reversal of 163645903680 is 86309546361.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (448).

It is a hoax number, since the sum of its digits (51) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 17447152 + ... + 17456528.

Almost surely, 2^163645903680 is an apocalyptic number.

163645903680 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 163645903680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (308708755200).

163645903680 is an abundant number, since it is smaller than the sum of its proper divisors (453771606720).

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

163645903680 is an equidigital number, since it uses as much as digits as its factorization.

163645903680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9471 (or 9447 counting only the distinct ones).

The product of its (nonzero) digits is 2799360, while the sum is 51.

The spelling of 163645903680 in words is "one hundred sixty-three billion, six hundred forty-five million, nine hundred three thousand, six hundred eighty".