11155105981 has 2 divisors, whose sum is σ = 11155105982. Its totient is φ = 11155105980.

The previous prime is 11155105963. The next prime is 11155106003. The reversal of 11155105981 is 18950155111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10251562500 + 903543481 = 101250^2 + 30059^2 .

It is an emirp because it is prime and its reverse (18950155111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11155105981 - 2²¹ = 11153008829 is a prime.

It is a super-3 number, since 3×11155105981³ (a number of 31 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 11155105981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11155105931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5577552990 + 5577552991.

It is an arithmetic number, because the mean of its divisors is an integer number (5577552991).

Almost surely, 2^11155105981 is an apocalyptic number.

It is an amenable number.

11155105981 is a deficient number, since it is larger than the sum of its proper divisors (1).

11155105981 is an equidigital number, since it uses as much as digits as its factorization.

11155105981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9000, while the sum is 37.

The spelling of 11155105981 in words is "eleven billion, one hundred fifty-five million, one hundred five thousand, nine hundred eighty-one".