78856384993 has 2 divisors, whose sum is σ = 78856384994. Its totient is φ = 78856384992.

The previous prime is 78856384991. The next prime is 78856385009. The reversal of 78856384993 is 39948365887.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52823207889 + 26033177104 = 229833^2 + 161348^2 .

It is a cyclic number.

It is not a de Polignac number, because 78856384993 - 2¹ = 78856384991 is a prime.

It is a super-2 number, since 2×78856384993² (a number of 23 digits) contains 22 as substring.

Together with 78856384991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (78856384991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39428192496 + 39428192497.

It is an arithmetic number, because the mean of its divisors is an integer number (39428192497).

Almost surely, 2^78856384993 is an apocalyptic number.

It is an amenable number.

78856384993 is a deficient number, since it is larger than the sum of its proper divisors (1).

78856384993 is an equidigital number, since it uses as much as digits as its factorization.

78856384993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 313528320, while the sum is 70.

The spelling of 78856384993 in words is "seventy-eight billion, eight hundred fifty-six million, three hundred eighty-four thousand, nine hundred ninety-three".