1281218683 has 2 divisors, whose sum is σ = 1281218684. Its totient is φ = 1281218682.

The previous prime is 1281218681. The next prime is 1281218699. The reversal of 1281218683 is 3868121821.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1281218683 - 2¹ = 1281218681 is a prime.

Together with 1281218681, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1281218681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640609341 + 640609342.

It is an arithmetic number, because the mean of its divisors is an integer number (640609342).

Almost surely, 2^1281218683 is an apocalyptic number.

1281218683 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281218683 is an equidigital number, since it uses as much as digits as its factorization.

1281218683 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36864, while the sum is 40.

The square root of 1281218683 is about 35794.1152006863. The cubic root of 1281218683 is about 1086.1115221911. Note that the first 3 decimals are identical.

The spelling of 1281218683 in words is "one billion, two hundred eighty-one million, two hundred eighteen thousand, six hundred eighty-three".