221221101021 has 16 divisors (see below), whose sum is σ = 295240366080. Its totient is φ = 147341355840.

The previous prime is 221221100987. The next prime is 221221101029. The reversal of 221221101021 is 120101122122.

It is not a de Polignac number, because 221221101021 - 2¹⁵ = 221221068253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221221101029) 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, 17452516 + ... + 17465186.

It is an arithmetic number, because the mean of its divisors is an integer number (18452522880).

Almost surely, 2^221221101021 is an apocalyptic number.

It is an amenable number.

221221101021 is a deficient number, since it is larger than the sum of its proper divisors (74019265059).

221221101021 is a wasteful number, since it uses less digits than its factorization.

221221101021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17716.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 221221101021 its reverse (120101122122), we get a palindrome (341322223143).

The spelling of 221221101021 in words is "two hundred twenty-one billion, two hundred twenty-one million, one hundred one thousand, twenty-one".