319278721 has 2 divisors, whose sum is σ = 319278722. Its totient is φ = 319278720.

The previous prime is 319278667. The next prime is 319278727. The reversal of 319278721 is 127872913.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 308388721 + 10890000 = 17561^2 + 3300^2 .

It is a cyclic number.

It is not a de Polignac number, because 319278721 - 2¹³ = 319270529 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (319278727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159639360 + 159639361.

It is an arithmetic number, because the mean of its divisors is an integer number (159639361).

Almost surely, 2^319278721 is an apocalyptic number.

It is an amenable number.

319278721 is a deficient number, since it is larger than the sum of its proper divisors (1).

319278721 is an equidigital number, since it uses as much as digits as its factorization.

319278721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42336, while the sum is 40.

The square root of 319278721 is about 17868.3720858952. The cubic root of 319278721 is about 683.4760880151.

The spelling of 319278721 in words is "three hundred nineteen million, two hundred seventy-eight thousand, seven hundred twenty-one".