18681673636289 has 2 divisors, whose sum is σ = 18681673636290. Its totient is φ = 18681673636288.

The previous prime is 18681673636267. The next prime is 18681673636309. The reversal of 18681673636289 is 98263637618681.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18598372131889 + 83301504400 = 4312583^2 + 288620^2 .

It is a cyclic number.

It is not a de Polignac number, because 18681673636289 - 2⁴⁴ = 1089487591873 is a prime.

It is not a weakly prime, because it can be changed into another prime (18681673636229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9340836818144 + 9340836818145.

It is an arithmetic number, because the mean of its divisors is an integer number (9340836818145).

Almost surely, 2^{18681673636289} is an apocalyptic number.

It is an amenable number.

18681673636289 is a deficient number, since it is larger than the sum of its proper divisors (1).

18681673636289 is an equidigital number, since it uses as much as digits as its factorization.

18681673636289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 752467968, while the sum is 74.

The spelling of 18681673636289 in words is "eighteen trillion, six hundred eighty-one billion, six hundred seventy-three million, six hundred thirty-six thousand, two hundred eighty-nine".