78506999 has 2 divisors, whose sum is σ = 78507000. Its totient is φ = 78506998.

The previous prime is 78506983. The next prime is 78507017. The reversal of 78506999 is 99960587.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78506999 - 2⁴ = 78506983 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78506999.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78506399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39253499 + 39253500.

It is an arithmetic number, because the mean of its divisors is an integer number (39253500).

Almost surely, 2^78506999 is an apocalyptic number.

78506999 is a deficient number, since it is larger than the sum of its proper divisors (1).

78506999 is an equidigital number, since it uses as much as digits as its factorization.

78506999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1224720, while the sum is 53.

The square root of 78506999 is about 8860.4175409514. The cubic root of 78506999 is about 428.1896105021.

The spelling of 78506999 in words is "seventy-eight million, five hundred six thousand, nine hundred ninety-nine".