18718635161 has 2 divisors, whose sum is σ = 18718635162. Its totient is φ = 18718635160.

The previous prime is 18718635139. The next prime is 18718635163. The reversal of 18718635161 is 16153681781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17907524761 + 811110400 = 133819^2 + 28480^2 .

It is a cyclic number.

It is not a de Polignac number, because 18718635161 - 2²⁶ = 18651526297 is a prime.

Together with 18718635163, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18718635163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9359317580 + 9359317581.

It is an arithmetic number, because the mean of its divisors is an integer number (9359317581).

Almost surely, 2^18718635161 is an apocalyptic number.

It is an amenable number.

18718635161 is a deficient number, since it is larger than the sum of its proper divisors (1).

18718635161 is an equidigital number, since it uses as much as digits as its factorization.

18718635161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 47.

The spelling of 18718635161 in words is "eighteen billion, seven hundred eighteen million, six hundred thirty-five thousand, one hundred sixty-one".