221121222021 has 12 divisors (see below), whose sum is σ = 365025509472. Its totient is φ = 126354983976.

The previous prime is 221121222001. The next prime is 221121222029. The reversal of 221121222021 is 120222121122.

It is a happy number.

221121222021 is a `hidden beast` number, since 2 + 211 + 212 + 220 + 21 = 666.

It is not a de Polignac number, because 221121222021 - 2²⁹ = 220584351109 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221121221985 and 221121222003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221121222029) 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, 1754930271 + ... + 1754930396.

It is an arithmetic number, because the mean of its divisors is an integer number (30418792456).

Almost surely, 2^221121222021 is an apocalyptic number.

221121222021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221121222021 is a deficient number, since it is larger than the sum of its proper divisors (143904287451).

221121222021 is a wasteful number, since it uses less digits than its factorization.

221121222021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3509860680 (or 3509860677 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 221121222021 its reverse (120222121122), we get a palindrome (341343343143).

The spelling of 221121222021 in words is "two hundred twenty-one billion, one hundred twenty-one million, two hundred twenty-two thousand, twenty-one".