11718786661 has 2 divisors, whose sum is σ = 11718786662. Its totient is φ = 11718786660.

The previous prime is 11718786659. The next prime is 11718786713. The reversal of 11718786661 is 16668781711.

It is a happy number.

It is an a-pointer prime, because the next prime (11718786713) can be obtained adding 11718786661 to its sum of digits (52).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10813920100 + 904866561 = 103990^2 + 30081^2 .

It is a cyclic number.

It is not a de Polignac number, because 11718786661 - 2¹ = 11718786659 is a prime.

Together with 11718786659, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 11718786599 and 11718786608.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11718786361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5859393330 + 5859393331.

It is an arithmetic number, because the mean of its divisors is an integer number (5859393331).

Almost surely, 2^11718786661 is an apocalyptic number.

It is an amenable number.

11718786661 is a deficient number, since it is larger than the sum of its proper divisors (1).

11718786661 is an equidigital number, since it uses as much as digits as its factorization.

11718786661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 677376, while the sum is 52.

The spelling of 11718786661 in words is "eleven billion, seven hundred eighteen million, seven hundred eighty-six thousand, six hundred sixty-one".