821541648163 has 4 divisors (see below), whose sum is σ = 821545823728. Its totient is φ = 821537472600.

The previous prime is 821541648133. The next prime is 821541648181. The reversal of 821541648163 is 361846145128.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 821541648163 - 2⁹ = 821541647651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (821541648133) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1777263 + ... + 2191288.

It is an arithmetic number, because the mean of its divisors is an integer number (205386455932).

Almost surely, 2^821541648163 is an apocalyptic number.

821541648163 is a deficient number, since it is larger than the sum of its proper divisors (4175565).

821541648163 is a wasteful number, since it uses less digits than its factorization.

821541648163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4175564.

The product of its digits is 1105920, while the sum is 49.

The spelling of 821541648163 in words is "eight hundred twenty-one billion, five hundred forty-one million, six hundred forty-eight thousand, one hundred sixty-three".