221101021202021 has 4 divisors (see below), whose sum is σ = 221102125598892. Its totient is φ = 221099916805152.

The previous prime is 221101021201909. The next prime is 221101021202161. The reversal of 221101021202021 is 120202120101122.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 182625114820996 + 38475906381025 = 13513886^2 + 6202895^2 .

It is a cyclic number.

It is not a de Polignac number, because 221101021202021 - 2¹⁴ = 221101021185637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221101021502021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 551898080 + ... + 552298553.

It is an arithmetic number, because the mean of its divisors is an integer number (55275531399723).

Almost surely, 2^{221101021202021} is an apocalyptic number.

It is an amenable number.

221101021202021 is a deficient number, since it is larger than the sum of its proper divisors (1104396871).

221101021202021 is a wasteful number, since it uses less digits than its factorization.

221101021202021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1104396870.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 221101021202021 its reverse (120202120101122), we get a palindrome (341303141303143).

The spelling of 221101021202021 in words is "two hundred twenty-one trillion, one hundred one billion, twenty-one million, two hundred two thousand, twenty-one".