78549494869 has 2 divisors, whose sum is σ = 78549494870. Its totient is φ = 78549494868.

The previous prime is 78549494861. The next prime is 78549494887. The reversal of 78549494869 is 96849494587.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77249531844 + 1299963025 = 277938^2 + 36055^2 .

It is a cyclic number.

It is not a de Polignac number, because 78549494869 - 2³ = 78549494861 is a prime.

It is a super-2 number, since 2×78549494869² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78549494861) 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, 39274747434 + 39274747435.

It is an arithmetic number, because the mean of its divisors is an integer number (39274747435).

Almost surely, 2^78549494869 is an apocalyptic number.

It is an amenable number.

78549494869 is a deficient number, since it is larger than the sum of its proper divisors (1).

78549494869 is an equidigital number, since it uses as much as digits as its factorization.

78549494869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 627056640, while the sum is 73.

The spelling of 78549494869 in words is "seventy-eight billion, five hundred forty-nine million, four hundred ninety-four thousand, eight hundred sixty-nine".