71111111 has 2 divisors, whose sum is σ = 71111112. Its totient is φ = 71111110.

The previous prime is 71111087. The next prime is 71111113. The reversal of 71111111 is 11111117.

It is a strong prime.

It is an emirp because it is prime and its reverse (11111117) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71111111 - 2¹⁰ = 71110087 is a prime.

Together with 71111113, it forms a pair of twin primes.

It is a Chen prime.

71111111 is a modest number, since divided by 11111 gives 711 as remainder.

It is a nialpdrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71111113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35555555 + 35555556.

It is an arithmetic number, because the mean of its divisors is an integer number (35555556).

Almost surely, 2^71111111 is an apocalyptic number.

71111111 is a deficient number, since it is larger than the sum of its proper divisors (1).

71111111 is an equidigital number, since it uses as much as digits as its factorization.

71111111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7, while the sum is 14.

The square root of 71111111 is about 8432.7404205276. The cubic root of 71111111 is about 414.2976672447.

Adding to 71111111 its reverse (11111117), we get a palindrome (82222228).

It can be divided in two parts, 7 and 1111111, that multiplied together give a palindrome (7777777).

The spelling of 71111111 in words is "seventy-one million, one hundred eleven thousand, one hundred eleven".