11117655781 has 2 divisors, whose sum is σ = 11117655782. Its totient is φ = 11117655780.

The previous prime is 11117655779. The next prime is 11117655793. The reversal of 11117655781 is 18755671111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8147950756 + 2969705025 = 90266^2 + 54495^2 .

It is a cyclic number.

It is not a de Polignac number, because 11117655781 - 2¹ = 11117655779 is a prime.

It is a super-2 number, since 2×11117655781² (a number of 21 digits) contains 22 as substring.

Together with 11117655779, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11117655881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5558827890 + 5558827891.

It is an arithmetic number, because the mean of its divisors is an integer number (5558827891).

Almost surely, 2^11117655781 is an apocalyptic number.

It is an amenable number.

11117655781 is a deficient number, since it is larger than the sum of its proper divisors (1).

11117655781 is an equidigital number, since it uses as much as digits as its factorization.

11117655781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 58800, while the sum is 43.

The spelling of 11117655781 in words is "eleven billion, one hundred seventeen million, six hundred fifty-five thousand, seven hundred eighty-one".