1281587 has 2 divisors, whose sum is σ = 1281588. Its totient is φ = 1281586.

The previous prime is 1281563. The next prime is 1281649. The reversal of 1281587 is 7851821.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1281587 - 2⁶ = 1281523 is a prime.

It is a Chen prime.

It is equal to p₉₈₇₁₇ and since 1281587 and 98717 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (1281547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640793 + 640794.

It is an arithmetic number, because the mean of its divisors is an integer number (640794).

2^1281587 is an apocalyptic number.

1281587 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281587 is an equidigital number, since it uses as much as digits as its factorization.

1281587 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4480, while the sum is 32.

The square root of 1281587 is about 1132.0719941770. The cubic root of 1281587 is about 108.6215588477.

The spelling of 1281587 in words is "one million, two hundred eighty-one thousand, five hundred eighty-seven".