221664121071 has 16 divisors (see below), whose sum is σ = 301171790304. Its totient is φ = 144967065984.

The previous prime is 221664121051. The next prime is 221664121093. The reversal of 221664121071 is 170121466122.

It is not a de Polignac number, because 221664121071 - 2¹¹ = 221664119023 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221664121051) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1054365 + ... + 1247001.

It is an arithmetic number, because the mean of its divisors is an integer number (18823236894).

Almost surely, 2^221664121071 is an apocalyptic number.

221664121071 is a deficient number, since it is larger than the sum of its proper divisors (79507669233).

221664121071 is a wasteful number, since it uses less digits than its factorization.

221664121071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199930.

The product of its (nonzero) digits is 8064, while the sum is 33.

Adding to 221664121071 its reverse (170121466122), we get a palindrome (391785587193).

The spelling of 221664121071 in words is "two hundred twenty-one billion, six hundred sixty-four million, one hundred twenty-one thousand, seventy-one".