211220011020181 has 2 divisors, whose sum is σ = 211220011020182. Its totient is φ = 211220011020180.

The previous prime is 211220011020173. The next prime is 211220011020191. The reversal of 211220011020181 is 181020110022112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 145652674882225 + 65567336137956 = 12068665^2 + 8097366^2 .

It is a cyclic number.

It is not a de Polignac number, because 211220011020181 - 2³ = 211220011020173 is a prime.

It is a super-2 number, since 2×211220011020181² (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 (211220011020191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610005510090 + 105610005510091.

It is an arithmetic number, because the mean of its divisors is an integer number (105610005510091).

Almost surely, 2^{211220011020181} is an apocalyptic number.

It is an amenable number.

211220011020181 is a deficient number, since it is larger than the sum of its proper divisors (1).

211220011020181 is an equidigital number, since it uses as much as digits as its factorization.

211220011020181 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 22.

Adding to 211220011020181 its reverse (181020110022112), we get a palindrome (392240121042293).

The spelling of 211220011020181 in words is "two hundred eleven trillion, two hundred twenty billion, eleven million, twenty thousand, one hundred eighty-one".