18778012811 has 2 divisors, whose sum is σ = 18778012812. Its totient is φ = 18778012810.

The previous prime is 18778012793. The next prime is 18778012831. The reversal of 18778012811 is 11821087781.

It is a weak prime.

It is an emirp because it is prime and its reverse (11821087781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18778012811 - 2¹⁰ = 18778011787 is a prime.

It is a super-2 number, since 2×18778012811² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18778012831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9389006405 + 9389006406.

It is an arithmetic number, because the mean of its divisors is an integer number (9389006406).

Almost surely, 2^18778012811 is an apocalyptic number.

18778012811 is a deficient number, since it is larger than the sum of its proper divisors (1).

18778012811 is an equidigital number, since it uses as much as digits as its factorization.

18778012811 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 50176, while the sum is 44.

The spelling of 18778012811 in words is "eighteen billion, seven hundred seventy-eight million, twelve thousand, eight hundred eleven".