2221112217781 has 2 divisors, whose sum is σ = 2221112217782. Its totient is φ = 2221112217780.

The previous prime is 2221112217769. The next prime is 2221112217799. The reversal of 2221112217781 is 1877122111222.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1282180287556 + 938931930225 = 1132334^2 + 968985^2 .

It is a cyclic number.

It is not a de Polignac number, because 2221112217781 - 2²¹ = 2221110120629 is a prime.

It is a super-2 number, since 2×2221112217781² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2221112217781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2221112217721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1110556108890 + 1110556108891.

It is an arithmetic number, because the mean of its divisors is an integer number (1110556108891).

Almost surely, 2^{2221112217781} is an apocalyptic number.

It is an amenable number.

2221112217781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2221112217781 is an equidigital number, since it uses as much as digits as its factorization.

2221112217781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12544, while the sum is 37.

The spelling of 2221112217781 in words is "two trillion, two hundred twenty-one billion, one hundred twelve million, two hundred seventeen thousand, seven hundred eighty-one".