163217920 has 80 divisors (see below), whose sum is σ = 395778240. Its totient is φ = 64548864.

The previous prime is 163217917. The next prime is 163217927. The reversal of 163217920 is 29712361.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-4 number, since 4×163217920⁴ (a number of 34 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (163217927) 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, 263371 + ... + 263989.

It is an arithmetic number, because the mean of its divisors is an integer number (4947228).

Almost surely, 2^163217920 is an apocalyptic number.

163217920 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 163217920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (197889120).

163217920 is an abundant number, since it is smaller than the sum of its proper divisors (232560320).

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

163217920 is an equidigital number, since it uses as much as digits as its factorization.

163217920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 745 (or 729 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 163217920 is about 12775.6768900908. The cubic root of 163217920 is about 546.4988843283.

The spelling of 163217920 in words is "one hundred sixty-three million, two hundred seventeen thousand, nine hundred twenty".