111021220212181 has 2 divisors, whose sum is σ = 111021220212182. Its totient is φ = 111021220212180.

The previous prime is 111021220212169. The next prime is 111021220212223. The reversal of 111021220212181 is 181212022120111.

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., 101901635593956 + 9119584618225 = 10094634^2 + 3019865^2 .

It is a cyclic number.

It is not a de Polignac number, because 111021220212181 - 2²¹ = 111021218115029 is a prime.

It is a super-2 number, since 2×111021220212181² (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 (111021220212481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55510610106090 + 55510610106091.

It is an arithmetic number, because the mean of its divisors is an integer number (55510610106091).

Almost surely, 2^{111021220212181} is an apocalyptic number.

It is an amenable number.

111021220212181 is a deficient number, since it is larger than the sum of its proper divisors (1).

111021220212181 is an equidigital number, since it uses as much as digits as its factorization.

111021220212181 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.

Adding to 111021220212181 its reverse (181212022120111), we get a palindrome (292233242332292).

The spelling of 111021220212181 in words is "one hundred eleven trillion, twenty-one billion, two hundred twenty million, two hundred twelve thousand, one hundred eighty-one".