221163891 has 8 divisors (see below), whose sum is σ = 317568720. Its totient is φ = 136100832.

The previous prime is 221163871. The next prime is 221163893. The reversal of 221163891 is 198361122.

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

It is not a de Polignac number, because 221163891 - 2¹⁰ = 221162867 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221163893) 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, 2835396 + ... + 2835473.

It is an arithmetic number, because the mean of its divisors is an integer number (39696090).

Almost surely, 2^221163891 is an apocalyptic number.

221163891 is a deficient number, since it is larger than the sum of its proper divisors (96404829).

221163891 is a wasteful number, since it uses less digits than its factorization.

221163891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5670885.

The product of its digits is 5184, while the sum is 33.

The square root of 221163891 is about 14871.5799765862. The cubic root of 221163891 is about 604.7437760269.

The spelling of 221163891 in words is "two hundred twenty-one million, one hundred sixty-three thousand, eight hundred ninety-one".