221977987191 has 8 divisors (see below), whose sum is σ = 328856277360. Its totient is φ = 147985324776.

The previous prime is 221977987163. The next prime is 221977987199. The reversal of 221977987191 is 191789779122.

It is not a de Polignac number, because 221977987191 - 2¹⁴ = 221977970807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221977987199) 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, 4110703440 + ... + 4110703493.

It is an arithmetic number, because the mean of its divisors is an integer number (41107034670).

Almost surely, 2^221977987191 is an apocalyptic number.

221977987191 is a deficient number, since it is larger than the sum of its proper divisors (106878290169).

221977987191 is an equidigital number, since it uses as much as digits as its factorization.

221977987191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8221406942 (or 8221406936 counting only the distinct ones).

The product of its digits is 8001504, while the sum is 63.

The spelling of 221977987191 in words is "two hundred twenty-one billion, nine hundred seventy-seven million, nine hundred eighty-seven thousand, one hundred ninety-one".