1281535 has 4 divisors (see below), whose sum is σ = 1537848. Its totient is φ = 1025224.

The previous prime is 1281523. The next prime is 1281541. The reversal of 1281535 is 5351821.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5351821 = 17 ⋅314813.

It is a cyclic number.

It is not a de Polignac number, because 1281535 - 2⁵ = 1281503 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128149 + ... + 128158.

It is an arithmetic number, because the mean of its divisors is an integer number (384462).

2^1281535 is an apocalyptic number.

1281535 is a deficient number, since it is larger than the sum of its proper divisors (256313).

1281535 is an equidigital number, since it uses as much as digits as its factorization.

1281535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256312.

The product of its digits is 1200, while the sum is 25.

The square root of 1281535 is about 1132.0490272069. The cubic root of 1281535 is about 108.6200897324.

The spelling of 1281535 in words is "one million, two hundred eighty-one thousand, five hundred thirty-five".