221050121921 has 2 divisors, whose sum is σ = 221050121922. Its totient is φ = 221050121920.

The previous prime is 221050121863. The next prime is 221050121939. The reversal of 221050121921 is 129121050122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 204723671296 + 16326450625 = 452464^2 + 127775^2 .

It is a cyclic number.

It is not a de Polignac number, because 221050121921 - 2¹⁰ = 221050120897 is a prime.

It is not a weakly prime, because it can be changed into another prime (221050129921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110525060960 + 110525060961.

It is an arithmetic number, because the mean of its divisors is an integer number (110525060961).

Almost surely, 2^221050121921 is an apocalyptic number.

It is an amenable number.

221050121921 is a deficient number, since it is larger than the sum of its proper divisors (1).

221050121921 is an equidigital number, since it uses as much as digits as its factorization.

221050121921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 26.

The spelling of 221050121921 in words is "two hundred twenty-one billion, fifty million, one hundred twenty-one thousand, nine hundred twenty-one".