163643821 has 8 divisors (see below), whose sum is σ = 178617024. Its totient is φ = 148686720.

The previous prime is 163643813. The next prime is 163643849. The reversal of 163643821 is 128346361.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 163643821 - 2³ = 163643813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163643861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29181 + ... + 34333.

It is an arithmetic number, because the mean of its divisors is an integer number (22327128).

Almost surely, 2^163643821 is an apocalyptic number.

163643821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

163643821 is a deficient number, since it is larger than the sum of its proper divisors (14973203).

163643821 is a wasteful number, since it uses less digits than its factorization.

163643821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8051.

The product of its digits is 20736, while the sum is 34.

The square root of 163643821 is about 12792.3344624818. The cubic root of 163643821 is about 546.9738163792.

The spelling of 163643821 in words is "one hundred sixty-three million, six hundred forty-three thousand, eight hundred twenty-one".