111201012211981 has 2 divisors, whose sum is σ = 111201012211982. Its totient is φ = 111201012211980.

The previous prime is 111201012211957. The next prime is 111201012212089. The reversal of 111201012211981 is 189112210102111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 101660536809225 + 9540475402756 = 10082685^2 + 3088766^2 .

It is a cyclic number.

It is not a de Polignac number, because 111201012211981 - 2¹⁷ = 111201012080909 is a prime.

It is a super-2 number, since 2×111201012211981² (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 (111201012211381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55600506105990 + 55600506105991.

It is an arithmetic number, because the mean of its divisors is an integer number (55600506105991).

Almost surely, 2^{111201012211981} is an apocalyptic number.

It is an amenable number.

111201012211981 is a deficient number, since it is larger than the sum of its proper divisors (1).

111201012211981 is an equidigital number, since it uses as much as digits as its factorization.

111201012211981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 31.

The spelling of 111201012211981 in words is "one hundred eleven trillion, two hundred one billion, twelve million, two hundred eleven thousand, nine hundred eighty-one".