306218493 has 18 divisors (see below), whose sum is σ = 514531134. Its totient is φ = 174981744.

The previous prime is 306218491. The next prime is 306218519. The reversal of 306218493 is 394812603.

It can be written as a sum of positive squares in only one way, i.e., 306005049 + 213444 = 17493^2 + 462^2 .

It is not a de Polignac number, because 306218493 - 2¹ = 306218491 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (306218491) 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 in 17 ways as a sum of consecutive naturals, for example, 346746 + ... + 347627.

It is an arithmetic number, because the mean of its divisors is an integer number (28585063).

Almost surely, 2^306218493 is an apocalyptic number.

It is an amenable number.

306218493 is a deficient number, since it is larger than the sum of its proper divisors (208312641).

306218493 is a wasteful number, since it uses less digits than its factorization.

306218493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 694393 (or 694383 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 306218493 is about 17499.0997768457. The cubic root of 306218493 is about 674.0267587342.

The spelling of 306218493 in words is "three hundred six million, two hundred eighteen thousand, four hundred ninety-three".