221173126221 has 16 divisors (see below), whose sum is σ = 296707138560. Its totient is φ = 146544536640.

The previous prime is 221173126201. The next prime is 221173126247. The reversal of 221173126221 is 122621371122.

It is not a de Polignac number, because 221173126221 - 2⁶ = 221173126157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221173126201) 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, 1420191 + ... + 1568211.

It is an arithmetic number, because the mean of its divisors is an integer number (18544196160).

Almost surely, 2^221173126221 is an apocalyptic number.

It is an amenable number.

221173126221 is a deficient number, since it is larger than the sum of its proper divisors (75534012339).

221173126221 is a wasteful number, since it uses less digits than its factorization.

221173126221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151076.

The product of its digits is 4032, while the sum is 30.

Adding to 221173126221 its reverse (122621371122), we get a palindrome (343794497343).

The spelling of 221173126221 in words is "two hundred twenty-one billion, one hundred seventy-three million, one hundred twenty-six thousand, two hundred twenty-one".