78656749 has 2 divisors, whose sum is σ = 78656750. Its totient is φ = 78656748.

The previous prime is 78656741. The next prime is 78656771. The reversal of 78656749 is 94765687.

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., 45995524 + 32661225 = 6782^2 + 5715^2 .

It is a cyclic number.

It is not a de Polignac number, because 78656749 - 2³ = 78656741 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 78656696 and 78656705.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78656741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39328374 + 39328375.

It is an arithmetic number, because the mean of its divisors is an integer number (39328375).

Almost surely, 2^78656749 is an apocalyptic number.

It is an amenable number.

78656749 is a deficient number, since it is larger than the sum of its proper divisors (1).

78656749 is an equidigital number, since it uses as much as digits as its factorization.

78656749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2540160, while the sum is 52.

The square root of 78656749 is about 8868.8640197040. The cubic root of 78656749 is about 428.4616909883.

The spelling of 78656749 in words is "seventy-eight million, six hundred fifty-six thousand, seven hundred forty-nine".