268319781 has 24 divisors (see below), whose sum is σ = 393321240. Its totient is φ = 176242176.

The previous prime is 268319759. The next prime is 268319783. The reversal of 268319781 is 187913862.

268319781 is a `hidden beast` number, since 268 + 319 + 78 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 124679556 + 143640225 = 11166^2 + 11985^2 .

It is not a de Polignac number, because 268319781 - 2⁶ = 268319717 is a prime.

It is a super-2 number, since 2×268319781² = 143991009751775922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (268319783) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 365691 + ... + 366423.

It is an arithmetic number, because the mean of its divisors is an integer number (16388385).

Almost surely, 2^268319781 is an apocalyptic number.

It is an amenable number.

268319781 is a deficient number, since it is larger than the sum of its proper divisors (125001459).

268319781 is a wasteful number, since it uses less digits than its factorization.

268319781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1285 (or 1282 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 268319781 is about 16380.4694987659. The cubic root of 268319781 is about 644.9869043673.

The spelling of 268319781 in words is "two hundred sixty-eight million, three hundred nineteen thousand, seven hundred eighty-one".