78966709 has 2 divisors, whose sum is σ = 78966710. Its totient is φ = 78966708.

The previous prime is 78966689. The next prime is 78966733. The reversal of 78966709 is 90766987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54066609 + 24900100 = 7353^2 + 4990^2 .

It is an emirp because it is prime and its reverse (90766987) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78966709 - 2⁵ = 78966677 is a prime.

It is a super-2 number, since 2×78966709² = 12471482260581362, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78966799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39483354 + 39483355.

It is an arithmetic number, because the mean of its divisors is an integer number (39483355).

Almost surely, 2^78966709 is an apocalyptic number.

It is an amenable number.

78966709 is a deficient number, since it is larger than the sum of its proper divisors (1).

78966709 is an equidigital number, since it uses as much as digits as its factorization.

78966709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1143072, while the sum is 52.

The square root of 78966709 is about 8886.3214549104. The cubic root of 78966709 is about 429.0237615048.

The spelling of 78966709 in words is "seventy-eight million, nine hundred sixty-six thousand, seven hundred nine".