221121022021 has 4 divisors (see below), whose sum is σ = 222529436332. Its totient is φ = 219712607712.

The previous prime is 221121021977. The next prime is 221121022027. The reversal of 221121022021 is 120220121122.

It is a happy number.

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 142818991396 + 78302030625 = 377914^2 + 279825^2 .

It is a cyclic number.

It is not a de Polignac number, because 221121022021 - 2⁹ = 221121021509 is a prime.

It is a super-2 number, since 2×221121022021² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221121021986 and 221121022004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221121022027) 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, 704206920 + ... + 704207233.

It is an arithmetic number, because the mean of its divisors is an integer number (55632359083).

Almost surely, 2^221121022021 is an apocalyptic number.

It is an amenable number.

221121022021 is a deficient number, since it is larger than the sum of its proper divisors (1408414311).

221121022021 is a wasteful number, since it uses less digits than its factorization.

221121022021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1408414310.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 221121022021 its reverse (120220121122), we get a palindrome (341341143143).

The spelling of 221121022021 in words is "two hundred twenty-one billion, one hundred twenty-one million, twenty-two thousand, twenty-one".