78115129 has 2 divisors, whose sum is σ = 78115130. Its totient is φ = 78115128.

The previous prime is 78115111. The next prime is 78115151. The reversal of 78115129 is 92151187.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74857104 + 3258025 = 8652^2 + 1805^2 .

It is an emirp because it is prime and its reverse (92151187) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78115129 - 2⁷ = 78115001 is a prime.

It is a super-2 number, since 2×78115129² = 12203946757373282, which contains 22 as substring.

It is equal to p_4565905 and since 78115129 and 4565905 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 78115094 and 78115103.

It is not a weakly prime, because it can be changed into another prime (78115529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39057564 + 39057565.

It is an arithmetic number, because the mean of its divisors is an integer number (39057565).

Almost surely, 2^78115129 is an apocalyptic number.

It is an amenable number.

78115129 is a deficient number, since it is larger than the sum of its proper divisors (1).

78115129 is an equidigital number, since it uses as much as digits as its factorization.

78115129 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5040, while the sum is 34.

The square root of 78115129 is about 8838.2763591098. The cubic root of 78115129 is about 427.4759814601.

The spelling of 78115129 in words is "seventy-eight million, one hundred fifteen thousand, one hundred twenty-nine".