78857739769 has 2 divisors, whose sum is σ = 78857739770. Its totient is φ = 78857739768.

The previous prime is 78857739743. The next prime is 78857739811. The reversal of 78857739769 is 96793775887.

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., 73083715600 + 5774024169 = 270340^2 + 75987^2 .

It is an emirp because it is prime and its reverse (96793775887) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78857739769 - 2¹³ = 78857731577 is a prime.

It is a super-2 number, since 2×78857739769² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78857739695 and 78857739704.

It is not a weakly prime, because it can be changed into another prime (78857709769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39428869884 + 39428869885.

It is an arithmetic number, because the mean of its divisors is an integer number (39428869885).

Almost surely, 2^78857739769 is an apocalyptic number.

It is an amenable number.

78857739769 is a deficient number, since it is larger than the sum of its proper divisors (1).

78857739769 is an equidigital number, since it uses as much as digits as its factorization.

78857739769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1120210560, while the sum is 76.

The spelling of 78857739769 in words is "seventy-eight billion, eight hundred fifty-seven million, seven hundred thirty-nine thousand, seven hundred sixty-nine".