221000221121021 has 4 divisors (see below), whose sum is σ = 221000388281052. Its totient is φ = 221000053960992.

The previous prime is 221000221121011. The next prime is 221000221121123. The reversal of 221000221121021 is 120121122000122.

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 61921003620100 + 159079217500921 = 7868990^2 + 12612661^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221000221121021 is a prime.

It is a super-3 number, since 3×221000221121021³ (a number of 44 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221000221121011) 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, 81580946 + ... + 84246371.

It is an arithmetic number, because the mean of its divisors is an integer number (55250097070263).

Almost surely, 2^{221000221121021} is an apocalyptic number.

It is an amenable number.

221000221121021 is a deficient number, since it is larger than the sum of its proper divisors (167160031).

221000221121021 is a wasteful number, since it uses less digits than its factorization.

221000221121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167160030.

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

Adding to 221000221121021 its reverse (120121122000122), we get a palindrome (341121343121143).

The spelling of 221000221121021 in words is "two hundred twenty-one trillion, two hundred twenty-one million, one hundred twenty-one thousand, twenty-one".