221121120021181 has 2 divisors, whose sum is σ = 221121120021182. Its totient is φ = 221121120021180.

The previous prime is 221121120021101. The next prime is 221121120021187. The reversal of 221121120021181 is 181120021121122.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 177409320001081 + 43711800020100 = 13319509^2 + 6611490^2 .

It is a cyclic number.

It is not a de Polignac number, because 221121120021181 - 2¹¹ = 221121120019133 is a prime.

It is a super-2 number, since 2×221121120021181² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221121120021187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110560560010590 + 110560560010591.

It is an arithmetic number, because the mean of its divisors is an integer number (110560560010591).

Almost surely, 2^{221121120021181} is an apocalyptic number.

It is an amenable number.

221121120021181 is a deficient number, since it is larger than the sum of its proper divisors (1).

221121120021181 is an equidigital number, since it uses as much as digits as its factorization.

221121120021181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 25.

The spelling of 221121120021181 in words is "two hundred twenty-one trillion, one hundred twenty-one billion, one hundred twenty million, twenty-one thousand, one hundred eighty-one".