313491781 has 8 divisors (see below), whose sum is σ = 340029144. Its totient is φ = 287854080.

The previous prime is 313491751. The next prime is 313491797. The reversal of 313491781 is 187194313.

It can be written as a sum of positive squares in 4 ways, for example, as 25341156 + 288150625 = 5034^2 + 16975^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 313491781 - 2¹⁷ = 313360709 is a prime.

It is a super-2 number, since 2×313491781² = 196554193509103922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 313491781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (313491751) 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 7 ways as a sum of consecutive naturals, for example, 224190 + ... + 225583.

It is an arithmetic number, because the mean of its divisors is an integer number (42503643).

Almost surely, 2^313491781 is an apocalyptic number.

It is an amenable number.

313491781 is a deficient number, since it is larger than the sum of its proper divisors (26537363).

313491781 is a wasteful number, since it uses less digits than its factorization.

313491781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 449831.

The product of its digits is 18144, while the sum is 37.

The square root of 313491781 is about 17705.6991107383. The cubic root of 313491781 is about 679.3215414418.

The spelling of 313491781 in words is "three hundred thirteen million, four hundred ninety-one thousand, seven hundred eighty-one".