78827689 has 2 divisors, whose sum is σ = 78827690. Its totient is φ = 78827688.

The previous prime is 78827687. The next prime is 78827719. The reversal of 78827689 is 98672887.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67322025 + 11505664 = 8205^2 + 3392^2 .

It is an emirp because it is prime and its reverse (98672887) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78827689 - 2¹ = 78827687 is a prime.

Together with 78827687, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (78827687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39413844 + 39413845.

It is an arithmetic number, because the mean of its divisors is an integer number (39413845).

Almost surely, 2^78827689 is an apocalyptic number.

It is an amenable number.

78827689 is a deficient number, since it is larger than the sum of its proper divisors (1).

78827689 is an equidigital number, since it uses as much as digits as its factorization.

78827689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2709504, while the sum is 55.

The square root of 78827689 is about 8878.4958748653. The cubic root of 78827689 is about 428.7718497876.

The spelling of 78827689 in words is "seventy-eight million, eight hundred twenty-seven thousand, six hundred eighty-nine".