78317468221 has 2 divisors, whose sum is σ = 78317468222. Its totient is φ = 78317468220.

The previous prime is 78317468213. The next prime is 78317468227. The reversal of 78317468221 is 12286471387.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56925188100 + 21392280121 = 238590^2 + 146261^2 .

It is a cyclic number.

It is not a de Polignac number, because 78317468221 - 2³ = 78317468213 is a prime.

It is a super-2 number, since 2×78317468221² (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 (78317468227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39158734110 + 39158734111.

It is an arithmetic number, because the mean of its divisors is an integer number (39158734111).

Almost surely, 2^78317468221 is an apocalyptic number.

It is an amenable number.

78317468221 is a deficient number, since it is larger than the sum of its proper divisors (1).

78317468221 is an equidigital number, since it uses as much as digits as its factorization.

78317468221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 903168, while the sum is 49.

The spelling of 78317468221 in words is "seventy-eight billion, three hundred seventeen million, four hundred sixty-eight thousand, two hundred twenty-one".