163216821 has 8 divisors (see below), whose sum is σ = 229076320. Its totient is φ = 103084272.

The previous prime is 163216811. The next prime is 163216877. The reversal of 163216821 is 128612361.

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

It is not a de Polignac number, because 163216821 - 2⁵ = 163216789 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 (163216811) 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, 1431670 + ... + 1431783.

It is an arithmetic number, because the mean of its divisors is an integer number (28634540).

Almost surely, 2^163216821 is an apocalyptic number.

It is an amenable number.

163216821 is a deficient number, since it is larger than the sum of its proper divisors (65859499).

163216821 is a wasteful number, since it uses less digits than its factorization.

163216821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2863475.

The product of its digits is 3456, while the sum is 30.

The square root of 163216821 is about 12775.6338785987. The cubic root of 163216821 is about 546.4976577399.

The spelling of 163216821 in words is "one hundred sixty-three million, two hundred sixteen thousand, eight hundred twenty-one".