221012221021221 has 12 divisors (see below), whose sum is σ = 342794465257632. Its totient is φ = 126292697726328.

The previous prime is 221012221021219. The next prime is 221012221021243. The reversal of 221012221021221 is 122120122210122.

It is not a de Polignac number, because 221012221021221 - 2¹ = 221012221021219 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221012221041221) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 751742248225 + ... + 751742248518.

It is an arithmetic number, because the mean of its divisors is an integer number (28566205438136).

Almost surely, 2^{221012221021221} is an apocalyptic number.

221012221021221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221012221021221 is a deficient number, since it is larger than the sum of its proper divisors (121782244236411).

221012221021221 is a wasteful number, since it uses less digits than its factorization.

221012221021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1503484496760 (or 1503484496753 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 221012221021221 its reverse (122120122210122), we get a palindrome (343132343231343).

The spelling of 221012221021221 in words is "two hundred twenty-one trillion, twelve billion, two hundred twenty-one million, twenty-one thousand, two hundred twenty-one".