1281965 has 4 divisors (see below), whose sum is σ = 1538364. Its totient is φ = 1025568.

The previous prime is 1281961. The next prime is 1281971. The reversal of 1281965 is 5691821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 662596 + 619369 = 814^2 + 787^2 .

It is a cyclic number.

It is not a de Polignac number, because 1281965 - 2² = 1281961 is a prime.

It is a super-2 number, since 2×1281965² = 3286868522450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128192 + ... + 128201.

It is an arithmetic number, because the mean of its divisors is an integer number (384591).

2^1281965 is an apocalyptic number.

It is an amenable number.

1281965 is a deficient number, since it is larger than the sum of its proper divisors (256399).

1281965 is an equidigital number, since it uses as much as digits as its factorization.

1281965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256398.

The product of its digits is 4320, while the sum is 32.

The square root of 1281965 is about 1132.2389323813. The cubic root of 1281965 is about 108.6322369921.

The spelling of 1281965 in words is "one million, two hundred eighty-one thousand, nine hundred sixty-five".