78878644331 has 2 divisors, whose sum is σ = 78878644332. Its totient is φ = 78878644330.

The previous prime is 78878644319. The next prime is 78878644357. The reversal of 78878644331 is 13344687887.

It is a weak prime.

It is an emirp because it is prime and its reverse (13344687887) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78878644331 is a prime.

It is a super-2 number, since 2×78878644331² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78878644231) 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, 39439322165 + 39439322166.

It is an arithmetic number, because the mean of its divisors is an integer number (39439322166).

Almost surely, 2^78878644331 is an apocalyptic number.

78878644331 is a deficient number, since it is larger than the sum of its proper divisors (1).

78878644331 is an equidigital number, since it uses as much as digits as its factorization.

78878644331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21676032, while the sum is 59.

The spelling of 78878644331 in words is "seventy-eight billion, eight hundred seventy-eight million, six hundred forty-four thousand, three hundred thirty-one".