221875861991 has 8 divisors (see below), whose sum is σ = 253599206784. Its totient is φ = 190159215480.

The previous prime is 221875861931. The next prime is 221875862017. The reversal of 221875861991 is 199168578122.

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 221875861991 - 2⁶ = 221875861927 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221875861991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221875861931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1603385 + ... + 1736258.

It is an arithmetic number, because the mean of its divisors is an integer number (31699900848).

Almost surely, 2^221875861991 is an apocalyptic number.

221875861991 is a deficient number, since it is larger than the sum of its proper divisors (31723344793).

221875861991 is an equidigital number, since it uses as much as digits as its factorization.

221875861991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3349141.

The product of its digits is 4354560, while the sum is 59.

The spelling of 221875861991 in words is "two hundred twenty-one billion, eight hundred seventy-five million, eight hundred sixty-one thousand, nine hundred ninety-one".