78740749 has 2 divisors, whose sum is σ = 78740750. Its totient is φ = 78740748.

The previous prime is 78740747. The next prime is 78740759. The reversal of 78740749 is 94704787.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40832100 + 37908649 = 6390^2 + 6157^2 .

It is a cyclic number.

It is not a de Polignac number, because 78740749 - 2¹ = 78740747 is a prime.

Together with 78740747, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 78740699 and 78740708.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78740741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39370374 + 39370375.

It is an arithmetic number, because the mean of its divisors is an integer number (39370375).

Almost surely, 2^78740749 is an apocalyptic number.

It is an amenable number.

78740749 is a deficient number, since it is larger than the sum of its proper divisors (1).

78740749 is an equidigital number, since it uses as much as digits as its factorization.

78740749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 395136, while the sum is 46.

The square root of 78740749 is about 8873.5984245401. The cubic root of 78740749 is about 428.6141592685.

The spelling of 78740749 in words is "seventy-eight million, seven hundred forty thousand, seven hundred forty-nine".