281326993 has 2 divisors, whose sum is σ = 281326994. Its totient is φ = 281326992.

The previous prime is 281326987. The next prime is 281327009. The reversal of 281326993 is 399623182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 279157264 + 2169729 = 16708^2 + 1473^2 .

It is a cyclic number.

It is not a de Polignac number, because 281326993 - 2¹⁷ = 281195921 is a prime.

It is not a weakly prime, because it can be changed into another prime (281326943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140663496 + 140663497.

It is an arithmetic number, because the mean of its divisors is an integer number (140663497).

Almost surely, 2^281326993 is an apocalyptic number.

It is an amenable number.

281326993 is a deficient number, since it is larger than the sum of its proper divisors (1).

281326993 is an equidigital number, since it uses as much as digits as its factorization.

281326993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 43.

The square root of 281326993 is about 16772.8051619280. The cubic root of 281326993 is about 655.2451293915.

The spelling of 281326993 in words is "two hundred eighty-one million, three hundred twenty-six thousand, nine hundred ninety-three".