78748669 has 2 divisors, whose sum is σ = 78748670. Its totient is φ = 78748668.

The previous prime is 78748667. The next prime is 78748679. The reversal of 78748669 is 96684787.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78092569 + 656100 = 8837^2 + 810^2 .

It is a cyclic number.

It is not a de Polignac number, because 78748669 - 2¹ = 78748667 is a prime.

It is a super-2 number, since 2×78748669² = 12402705738543122, which contains 22 as substring.

Together with 78748667, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78748661) 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, 39374334 + 39374335.

It is an arithmetic number, because the mean of its divisors is an integer number (39374335).

Almost surely, 2^78748669 is an apocalyptic number.

It is an amenable number.

78748669 is a deficient number, since it is larger than the sum of its proper divisors (1).

78748669 is an equidigital number, since it uses as much as digits as its factorization.

78748669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4064256, while the sum is 55.

The square root of 78748669 is about 8874.0446809783. The cubic root of 78748669 is about 428.6285292543.

The spelling of 78748669 in words is "seventy-eight million, seven hundred forty-eight thousand, six hundred sixty-nine".