318705421 has 2 divisors, whose sum is σ = 318705422. Its totient is φ = 318705420.

The previous prime is 318705367. The next prime is 318705437. The reversal of 318705421 is 124507813.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 307616521 + 11088900 = 17539^2 + 3330^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-318705421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (318705461) 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, 159352710 + 159352711.

It is an arithmetic number, because the mean of its divisors is an integer number (159352711).

Almost surely, 2^318705421 is an apocalyptic number.

It is an amenable number.

318705421 is a deficient number, since it is larger than the sum of its proper divisors (1).

318705421 is an equidigital number, since it uses as much as digits as its factorization.

318705421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 318705421 is about 17852.3225659856. The cubic root of 318705421 is about 683.0667574642.

The spelling of 318705421 in words is "three hundred eighteen million, seven hundred five thousand, four hundred twenty-one".