221814321891 has 8 divisors (see below), whose sum is σ = 296804930064. Its totient is φ = 147349964160.

The previous prime is 221814321889. The next prime is 221814321977. The reversal of 221814321891 is 198123418122.

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

It is not a de Polignac number, because 221814321891 - 2¹ = 221814321889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221814323891) 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, 131561626 + ... + 131563311.

It is an arithmetic number, because the mean of its divisors is an integer number (37100616258).

Almost surely, 2^221814321891 is an apocalyptic number.

221814321891 is a deficient number, since it is larger than the sum of its proper divisors (74990608173).

221814321891 is a wasteful number, since it uses less digits than its factorization.

221814321891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263125221.

The product of its digits is 55296, while the sum is 42.

The spelling of 221814321891 in words is "two hundred twenty-one billion, eight hundred fourteen million, three hundred twenty-one thousand, eight hundred ninety-one".