78111111011 has 2 divisors, whose sum is σ = 78111111012. Its totient is φ = 78111111010.

The previous prime is 78111111007. The next prime is 78111111017. The reversal of 78111111011 is 11011111187.

It is a weak prime.

It is an emirp because it is prime and its reverse (11011111187) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78111111011 - 2² = 78111111007 is a prime.

It is a super-2 number, since 2×78111111011² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78111111017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39055555505 + 39055555506.

It is an arithmetic number, because the mean of its divisors is an integer number (39055555506).

Almost surely, 2^78111111011 is an apocalyptic number.

78111111011 is a deficient number, since it is larger than the sum of its proper divisors (1).

78111111011 is an equidigital number, since it uses as much as digits as its factorization.

78111111011 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56, while the sum is 23.

Adding to 78111111011 its reverse (11011111187), we get a palindrome (89122222198).

The spelling of 78111111011 in words is "seventy-eight billion, one hundred eleven million, one hundred eleven thousand, eleven".