78251111 has 2 divisors, whose sum is σ = 78251112. Its totient is φ = 78251110.

The previous prime is 78251093. The next prime is 78251123. The reversal of 78251111 is 11115287.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78251111 - 2²⁶ = 11142247 is a prime.

It is a super-2 number, since 2×78251111² = 12246472745468642, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78251141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39125555 + 39125556.

It is an arithmetic number, because the mean of its divisors is an integer number (39125556).

Almost surely, 2^78251111 is an apocalyptic number.

78251111 is a deficient number, since it is larger than the sum of its proper divisors (1).

78251111 is an equidigital number, since it uses as much as digits as its factorization.

78251111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 560, while the sum is 26.

The square root of 78251111 is about 8845.9658036870. The cubic root of 78251111 is about 427.7238862390.

Adding to 78251111 its reverse (11115287), we get a palindrome (89366398).

The spelling of 78251111 in words is "seventy-eight million, two hundred fifty-one thousand, one hundred eleven".