268649581 has 2 divisors, whose sum is σ = 268649582. Its totient is φ = 268649580.

The previous prime is 268649573. The next prime is 268649639. The reversal of 268649581 is 185946862.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164711556 + 103938025 = 12834^2 + 10195^2 .

It is a cyclic number.

It is not a de Polignac number, because 268649581 - 2³ = 268649573 is a prime.

It is a super-2 number, since 2×268649581² = 144345194742951122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (268649561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 134324790 + 134324791.

It is an arithmetic number, because the mean of its divisors is an integer number (134324791).

Almost surely, 2^268649581 is an apocalyptic number.

It is an amenable number.

268649581 is a deficient number, since it is larger than the sum of its proper divisors (1).

268649581 is an equidigital number, since it uses as much as digits as its factorization.

268649581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 829440, while the sum is 49.

The square root of 268649581 is about 16390.5332738139. The cubic root of 268649581 is about 645.2510538429.

The spelling of 268649581 in words is "two hundred sixty-eight million, six hundred forty-nine thousand, five hundred eighty-one".