221002020181 has 2 divisors, whose sum is σ = 221002020182. Its totient is φ = 221002020180.

The previous prime is 221002020137. The next prime is 221002020191. The reversal of 221002020181 is 181020200122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 217031129956 + 3970890225 = 465866^2 + 63015^2 .

It is a cyclic number.

It is not a de Polignac number, because 221002020181 - 2¹⁵ = 221001987413 is a prime.

It is a super-2 number, since 2×221002020181² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221002020191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110501010090 + 110501010091.

It is an arithmetic number, because the mean of its divisors is an integer number (110501010091).

Almost surely, 2^221002020181 is an apocalyptic number.

It is an amenable number.

221002020181 is a deficient number, since it is larger than the sum of its proper divisors (1).

221002020181 is an equidigital number, since it uses as much as digits as its factorization.

221002020181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 19.

The spelling of 221002020181 in words is "two hundred twenty-one billion, two million, twenty thousand, one hundred eighty-one".