84778469317 has 2 divisors, whose sum is σ = 84778469318. Its totient is φ = 84778469316.

The previous prime is 84778469309. The next prime is 84778469327. The reversal of 84778469317 is 71396487748.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76216853476 + 8561615841 = 276074^2 + 92529^2 .

It is a cyclic number.

It is not a de Polignac number, because 84778469317 - 2³ = 84778469309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84778469327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42389234658 + 42389234659.

It is an arithmetic number, because the mean of its divisors is an integer number (42389234659).

Almost surely, 2^84778469317 is an apocalyptic number.

It is an amenable number.

84778469317 is a deficient number, since it is larger than the sum of its proper divisors (1).

84778469317 is an equidigital number, since it uses as much as digits as its factorization.

84778469317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56899584, while the sum is 64.

The spelling of 84778469317 in words is "eighty-four billion, seven hundred seventy-eight million, four hundred sixty-nine thousand, three hundred seventeen".